DAG-Edit 1.419 rev 3 09:08:2005 16:02 zea_mays_anatomy 1.0 gwg autogenerated-by: DAG-Edit version 1.410 date: Thu Feb 12 16:13:57 CST 2004 saved-by: Leszek version: $Revision: 1.1 $ definition database_cross_reference has_obo_format_version has_obo_namespace has_related_synonym zea_mays_anatomy is_a is a zea_mays_anatomy part_of Part of zea_mays_anatomy DERIVED/DEVELOPS_FROM Derived/Develops from zea_mays_anatomy ZEA:0015001 adaxial ZEA:0015001 zea_mays_anatomy ZEA:0015002 leaf blade indumentum ZEA:0015002 The ligule projections occur along the distal edge of the ligule and comprise numerous epidermal cell projections, forming a microscopic 'fringe' of projections. DELTA:Grass Character List zea_mays_anatomy ciliolate ligule ligule apex ZEA:0015003 ligule projections ZEA:0015003 The ligule projections occur along the distal edge of the ligule and comprise numerous epidermal cell projections, forming a microscopic 'fringe' of projections. MaizeGDB:165572 MaizeGDB:60922 The lateral veins make up the majority of the vasculature of the leaf sheath. They occur on either side of the midvein (which is only distinguishable from the lateral veins on the basis of position). zea_mays_anatomy ZEA:0015004 lateral vein ZEA:0015004 The lateral veins make up the majority of the vasculature of the leaf sheath. They occur on either side of the midvein (which is only distinguishable from the lateral veins on the basis of position). MaizeGDB:165572 MaizeGDB:60922 The midvein in the leaf sheath region of the leaf is seemingly the same diameter as the neighboring lateral veins and is indistinguishable from the lateral veins except on the basis of position. zea_mays_anatomy ZEA:0015005 midvein ZEA:0015005 The midvein in the leaf sheath region of the leaf is seemingly the same diameter as the neighboring lateral veins and is indistinguishable from the lateral veins except on the basis of position. MaizeGDB:60922 zea_mays_anatomy ZEA:0015006 bulliform cell ZEA:0015006 The ligule is a unique line of epidermal tissue and appears to be composed of 'fused hairs'. The ligule is oriented almost perpendicular to the adjacent leaf surface. zea_mays_anatomy ZEA:0015007 ligule appearance ZEA:0015007 The ligule is a unique line of epidermal tissue and appears to be composed of 'fused hairs'. The ligule is oriented almost perpendicular to the adjacent leaf surface. MaizeGDB:lv (ID# 165572) silica and cork short cells. zea_mays_anatomy ZEA:0015008 short cell ZEA:0015008 silica and cork short cells. MaizeGDB:60922 The ligule in Zea mays is a protruding line of tissue on the inner/upper (adaxial) surface of the leaf at the boundary between the leaf-sheath and the leaf blade (lamina) - the ligular region of the leaf. This unique line of epidermal tissue appears to be composed of 'fused hairs'. The ligule is oriented almost perpendicular to the adjacent leaf surface. MaizeDB:64473 zea_mays_anatomy ZEA:0015009 ligule ZEA:0015009 The ligule in Zea mays is a protruding line of tissue on the inner/upper (adaxial) surface of the leaf at the boundary between the leaf-sheath and the leaf blade (lamina) - the ligular region of the leaf. This unique line of epidermal tissue appears to be composed of 'fused hairs'. The ligule is oriented almost perpendicular to the adjacent leaf surface. A. Fahn:(1982). Plant Anatomy , p.244-245 , ISBN 0-08-028029-3 Gibbs Russell et al.:(1990). Grasses of Southern Africa , ISBN 0-620-14846-2 M. Freeling & B. Lane:1994. The Maize Leaf. In M. Freeling & V. Walbot (eds.) (1994). The Maize Handbook. Springer-Verlag , New York , ISBN 3-540-97826-7 MaizeGDB:lv (ID # 165572) zea_mays_anatomy ZEA:0015010 intercostal long cell ZEA:0015010 Provide defn. MaizeDB:45980 zea_mays_anatomy ZEA:0015011 leaf blade cuticle ZEA:0015011 Provide defn. ***:***** zea_mays_anatomy ZEA:0015012 costal long cell ZEA:0015012 Trichomes (hairs) which are present at the distal and proximal ends of the margin of the auricle. MaizeDB:165572 zea_mays_anatomy auricular setae ZEA:0015013 auricular trichomes ZEA:0015013 Trichomes (hairs) which are present at the distal and proximal ends of the margin of the auricle. MaizeGDB:165572 zea_mays_anatomy ZEA:0015014 cell type ZEA:0015014 zea_mays_anatomy ZEA:0015015 abaxial indumentum ZEA:0015015 A vein that arises from one of the primary intermediate veins and conducts in a basipetal direction. zea_mays_anatomy ZEA:0015016 intermediate vein ZEA:0015016 A vein that arises from one of the primary intermediate veins and conducts in a basipetal direction. MaizeGDB:165572 MaizeGDB:60922 zea_mays_anatomy ZEA:0015017 adaxial indumentum ZEA:0015017 zea_mays_anatomy ZEA:0015018 abaxial ZEA:0015018 zea_mays_anatomy ZEA:0015019 adaxial ZEA:0015019 zea_mays_anatomy ZEA:0015020 prickle hair ZEA:0015020 zea_mays_anatomy ZEA:0015021 leaf sheath indumentum ZEA:0015021 Provide definition MaizeDB:65488 XXX:12345 zea_mays_anatomy Leaf margin ZEA:0015022 leaf blade margin ZEA:0015022 Provide definition ****:**** Microhairs originate from one of the epidermal cells.... About 15um in length. zea_mays_anatomy ZEA:0015023 microhair ZEA:0015023 Microhairs originate from one of the epidermal cells.... About 15um in length. MaizeGDB:165572 MaizeGDB:60922 The proximal (basal) portion of the leaf that initiates at the culm node and wraps around the stem and extending to the ligule (adaxial surface) and collar (abaxial surface) regions of the leaf. Distal to this junction region is the lamina (leaf blade). MaizeDB:13810 zea_mays_anatomy ZEA:0015024 leaf sheath ZEA:0015024 The proximal (basal) portion of the leaf that initiates at the culm node and wraps around the stem and extending to the ligule (adaxial surface) and collar (abaxial surface) regions of the leaf. Distal to this junction region is the lamina (leaf blade). MaizeGDB:lv (ID # 165572) The epidermal tissue that is coincident with the auricular region of the lamina. zea_mays_anatomy ZEA:0015025 auricle epidermis ZEA:0015025 The epidermal tissue that is coincident with the auricular region of the lamina. MaizeGDB:165572 MaizeGDB:60922 A vein that arises from the midvein or one of the lateral veins. Usually only one intermediate vein can be found between any adjacent pair of lateral veins. zea_mays_anatomy ZEA:0015026 intermediate vein ZEA:0015026 A vein that arises from the midvein or one of the lateral veins. Usually only one intermediate vein can be found between any adjacent pair of lateral veins. MaizeGDB:165572 MaizeGDB:60922 Expanded lateral outgrowth of the stem produced in succession from the growing point, and having a bud in its axil. The maize foliar leaf consists of 2 distict parts, the blade (lamina) (a flat portion extending away from the stem (culm), which is the distal part of the whole leaf, and the sheath (a basal part wrapped tightly around the stem), which is the proximal part of the whole leaf. At the junction of blade (lamina) and sheath is an indentation and a hinge of translucent tissue. Each leaf has a pair of auricles. The auricles are triangular portions of leaf tissue that are adjacent to the indentation (junction of leaf sheath with leaf blade). Each leaf has a ligule. The ligule is a thin collar of filmy tissue which grows semi perpendicularly from the junction of the leaf sheath and leaf blade on the adaxial (upper) surface of the leaf. MaizeDB:24740 ZEA:0015059 zea_mays_anatomy lamina ZEA:0015027 leaf blade ZEA:0015027 Expanded lateral outgrowth of the stem produced in succession from the growing point, and having a bud in its axil. The maize foliar leaf consists of 2 distict parts, the blade (lamina) (a flat portion extending away from the stem (culm), which is the distal part of the whole leaf, and the sheath (a basal part wrapped tightly around the stem), which is the proximal part of the whole leaf. At the junction of blade (lamina) and sheath is an indentation and a hinge of translucent tissue. Each leaf has a pair of auricles. The auricles are triangular portions of leaf tissue that are adjacent to the indentation (junction of leaf sheath with leaf blade). Each leaf has a ligule. The ligule is a thin collar of filmy tissue which grows semi perpendicularly from the junction of the leaf sheath and leaf blade on the adaxial (upper) surface of the leaf. S. Poethig:1982. In W.F. Sheridan (ed.) , Maize for biological research , p.9-18. Plant Mol. Biol. Assn. , Charlottesville , VA. Provide a definition for this. MaizeDB:163501 zea_mays_anatomy Arrangement ZEA:0015028 phyllotaxy ZEA:0015028 Provide a definition for this. ZEA:Provide a defn. for this. A vein that arises from the midvein or one of the lateral veins. zea_mays_anatomy ZEA:0015029 primary intermediate vein ZEA:0015029 A vein that arises from the midvein or one of the lateral veins. MaizeGDB:165572 MaizeGDB:60922 One of the many veins which traverse the length of the leaf, running parallel to the midrib. zea_mays_anatomy ZEA:0015030 lateral vein ZEA:0015030 One of the many veins which traverse the length of the leaf, running parallel to the midrib. MaizeGDB:60922 The Zea mays leaf consists of 3 parts: the sheath which envelops the culm; the blade (lamina) which extends from the sheath; the collar and ligule located at the junction of the sheath and the blade (lamina). Ref.: Gibbs Russell et al. 1990, Grasses of southern Africa, p.7; ISBN: 0-620-14846-2. zea_mays_anatomy ZEA:0015031 leaf ZEA:0015031 The Zea mays leaf consists of 3 parts: the sheath which envelops the culm; the blade (lamina) which extends from the sheath; the collar and ligule located at the junction of the sheath and the blade (lamina). Ref.: Gibbs Russell et al. 1990, Grasses of southern Africa, p.7; ISBN: 0-620-14846-2. MaizeGDB:lv zea_mays_anatomy ZEA:0015032 midvein ZEA:0015032 Provide defn. zea_mays_anatomy Vasculature ZEA:0015033 leaf blade venation ZEA:0015033 Provide defn. 2222:33333 The root system of Zea mays is a complex organ. While most of it arises from the basal portion of the plant below ground, a considerable number of above-ground adventitious roots also contribute significantly to the volume of the root system. below-ground zea_mays_anatomy ZEA:0015034 root ZEA:0015034 The root system of Zea mays is a complex organ. While most of it arises from the basal portion of the plant below ground, a considerable number of above-ground adventitious roots also contribute significantly to the volume of the root system. below-ground MaizeGDB:lv Leaf blade auricles are small appendages (portion of leaf tissue) in the collar area of the leaf (proximal end (base) of the lamina (leaf blade)) immediately lateral to the ligule. In Zea mays the auricles appear to arise from the 'collar' tissue of the leaf blade. Each auricle has an equilateral triangular shape. The base of the triangle forming the proximal margin of the leaf, the upper equilateral side being the boundary of the proximal region of the leaf blade. The lower equilateral side being the boundary of the distal edge of the leaf sheath. There are two auricles on each adult leaf of Zea mays. The auricular tissue extends from the adaxial to the abaxial surfaces of the lamina. zea_mays_anatomy ZEA:0015035 leaf blade auricles ZEA:0015035 Leaf blade auricles are small appendages (portion of leaf tissue) in the collar area of the leaf (proximal end (base) of the lamina (leaf blade)) immediately lateral to the ligule. In Zea mays the auricles appear to arise from the 'collar' tissue of the leaf blade. Each auricle has an equilateral triangular shape. The base of the triangle forming the proximal margin of the leaf, the upper equilateral side being the boundary of the proximal region of the leaf blade. The lower equilateral side being the boundary of the distal edge of the leaf sheath. There are two auricles on each adult leaf of Zea mays. The auricular tissue extends from the adaxial to the abaxial surfaces of the lamina. ISBN:0620148462 MaizeGDB:165572 MaizeGDB:60922 The Zea mays Plant Structure Ontology consists of controlled vocabulary terms for Zea mays anatomy (including morphology). Note that the name Plant Structure Ontology is used in preference to Anatomy Ontology as plant scientists differ on the appropriate use of the term 'anatomy'. In the strict sense 'anatomy' includes 'morphology'. However, some plant scientists relate more easily to external features being termed morphology & internal features being termed anatomy. To overcome possible misunderstanding 'Plant Structure' is being used as the preferred term with 'Anatomy (incl. morphology)' as a synonym. maizedb:pldv (ID#165572) zea_mays_anatomy anatomy (including morphology) ZEA:0015036 Zea mays Plant Structure Ontology ZEA:0015036 The Zea mays Plant Structure Ontology consists of controlled vocabulary terms for Zea mays anatomy (including morphology). Note that the name Plant Structure Ontology is used in preference to Anatomy Ontology as plant scientists differ on the appropriate use of the term 'anatomy'. In the strict sense 'anatomy' includes 'morphology'. However, some plant scientists relate more easily to external features being termed morphology & internal features being termed anatomy. To overcome possible misunderstanding 'Plant Structure' is being used as the preferred term with 'Anatomy (incl. morphology)' as a synonym. MaizeGDB:lv (ID # 165572 zea_mays_anatomy ZEA:0015037 whole plant ZEA:0015037 The vascular tissue which forms distinct veins in the leaf sheath. The midvein is seemingly the same diameter as the lateral veins and is indistinguishable from the lateral veins except on the basis of location. MaizeDB:pending zea_mays_anatomy vasculature ZEA:0015039 leaf sheath venation ZEA:0015039 The vascular tissue which forms distinct veins in the leaf sheath. The midvein is seemingly the same diameter as the lateral veins and is indistinguishable from the lateral veins except on the basis of location. 2222:33333 Trichome produced in midrib region on adaxial surface of mature leaf. zea_mays_anatomy ZEA:0015040 macrohair ZEA:0015040 Trichome produced in midrib region on adaxial surface of mature leaf. MaizeGDB:60922 Provide defn. MaizeDB:69813 zea_mays_anatomy Leaf angle ZEA:0015041 leaf blade angle ZEA:0015041 Provide defn. ****:***** Provide defn. MaizeDB:104000 zea_mays_anatomy Leaf epidermis ZEA:0015042 leaf blade epidermis ZEA:0015042 Provide defn. ****:***** Provide defn. MaizeDB:64474 zea_mays_anatomy ZEA:0015043 leaf blade midrib ZEA:0015043 Provide defn. ****:***** zea_mays_anatomy ZEA:0015044 subsidiary cell ZEA:0015044 Provide defn. MaizeDB:246363 zea_mays_anatomy Leaf color ZEA:0015045 leaf blade color ZEA:0015045 Provide defn. ****:***** zea_mays_anatomy ZEA:0015046 guard cell ZEA:0015046 Provide defn. MaizeDB:24738 zea_mays_anatomy Leaf tip ZEA:0015047 leaf blade apex ZEA:0015047 Provide defn. ***:***** zea_mays_anatomy ZEA:0015048 stomatal complex ZEA:0015048 Trichome found in the midrib region on the adaxial surface of a mature leaf. zea_mays_anatomy ZEA:0015049 macrohair ZEA:0015049 Trichome found in the midrib region on the adaxial surface of a mature leaf. MaizeGDB:60922 A natural part or structure in a plant, capable of performing some special action (termed its function), which is essential to the life or well-being of the whole; as, the root, stem, leaves etc, are organs of plants. zea_mays_anatomy ZEA:0015050 organ ZEA:0015050 A natural part or structure in a plant, capable of performing some special action (termed its function), which is essential to the life or well-being of the whole; as, the root, stem, leaves etc, are organs of plants. :http //cancerweb.ncl.ac.uk/cgi-bin/omd?query=organ The trichomes (hairs) that occur at the margin of the distal end of the leaf sheath - adjacent to the base of the ligule and the proximal edge of the auricular region. zea_mays_anatomy ZEA:0015051 leaf sheath oral hairs ZEA:0015051 The trichomes (hairs) that occur at the margin of the distal end of the leaf sheath - adjacent to the base of the ligule and the proximal edge of the auricular region. MaizeGDB:165572 MaizeGDB:60922 The line of yellow tissue between the leaf sheath and the lamina on the abaxial surface of the leaf (equivalent to the proximal edge of the auricular region). MaizeDB:pending zea_mays_anatomy ZEA:0015052 leaf blade collar ZEA:0015052 The line of yellow tissue between the leaf sheath and the lamina on the abaxial surface of the leaf (equivalent to the proximal edge of the auricular region). Chapman:ISBN 0851991114 Covering, usually of hairs (trichomes) on the surface. zea_mays_anatomy ZEA:0015053 abaxial indumentum ZEA:0015053 Covering, usually of hairs (trichomes) on the surface. MaizeGDB:165572 Microhairs originate from one of the epidermal cells.... zea_mays_anatomy ZEA:0015054 microhair ZEA:0015054 Microhairs originate from one of the epidermal cells.... MaizeGDB:60922 Covering, usually of hairs (trichomes) on the surface. zea_mays_anatomy ZEA:0015055 adaxial indumentum ZEA:0015055 Covering, usually of hairs (trichomes) on the surface. MaizeGDB:lv 165572 zea_mays_anatomy ZEA:0015056 abaxial ZEA:0015056 zea_mays_anatomy ZEA:0015057 ligule indumentum ZEA:0015057 This descriptor refers to whether the ligule is hyaline, membranous, scarious... zea_mays_anatomy ZEA:0015058 ligule consistency ZEA:0015058 This descriptor refers to whether the ligule is hyaline, membranous, scarious... DELTA:Grass Character List MaizeGDB:165572 Juvenile leaves are distinct from adult leaves in maize. The juvenile vs adult status is characterized by particular anatomical traits: wax and hair distribution, presence or absence of epidermal cell types, cell wall shape and biochemistry. The juvenile leaves include the oldest leaves. The first 5 juvenile leaves are representative of the 5 embryonic leaves found in the maize kernel (caryopsis). The distinctness of these 5 embryonic leaves is not yet represented in the ontology. The change from juvenile- phase to adult-phase leaves is gradual. zea_mays_anatomy ZEA:0015059 juvenile leaf ZEA:0015059 Juvenile leaves are distinct from adult leaves in maize. The juvenile vs adult status is characterized by particular anatomical traits: wax and hair distribution, presence or absence of epidermal cell types, cell wall shape and biochemistry. The juvenile leaves include the oldest leaves. The first 5 juvenile leaves are representative of the 5 embryonic leaves found in the maize kernel (caryopsis). The distinctness of these 5 embryonic leaves is not yet represented in the ontology. The change from juvenile- phase to adult-phase leaves is gradual. Freeling & Lane:The Maize Leaf. In The Maize Handbook , ISBN 0387978267 MaizeGDB:lv Sylvester et al.:American Journal of Botany 88(12) 2157-2167 , 2001 The adult leaves are above the juvenile (oldest) leaves. Adult leaves are distinct from juvenile leaves in maize. The juvenile vs adult status is characterized by particular anatomical traits: wax and hair distribution, presence or absence of epidermal cell types, cell wall shape and biochemistry. The change from juvenile-phase to adult-phase leaves is gradual. zea_mays_anatomy ZEA:0015060 adult leaf ZEA:0015060 The adult leaves are above the juvenile (oldest) leaves. Adult leaves are distinct from juvenile leaves in maize. The juvenile vs adult status is characterized by particular anatomical traits: wax and hair distribution, presence or absence of epidermal cell types, cell wall shape and biochemistry. The change from juvenile-phase to adult-phase leaves is gradual. Freeling & Lane:The Maize Leaf. In The Maize Handbook. ISBN 0387978267 MaizeGDB:lv Sylvester et al.:American Journal of Botan 88(12) 2157-2167 , 2001 The primary root (radicle or tap root) is the initial root structure which emerges from the embryo of the caryopsis (kernel/seed). The primary root is formed early during embryogenesis, becoming defined as a distinctive region 10-15 days after pollination. The primary root is enclosed by a protective ensheathing structure, the coleorhiza. A variable number of adventitious lateral roots arise from the primary root (these are not formed during embryogenesis). See 'lateral root' for further information on lateral roots (seminal lateral roots). These lateral roots arise at varying points behind the zone of root hair formation on the primary root. The primary root is always present (except when killed by some injury e.g. freezing). zea_mays_anatomy radicle ZEA:0015061 primary root ZEA:0015061 The primary root (radicle or tap root) is the initial root structure which emerges from the embryo of the caryopsis (kernel/seed). The primary root is formed early during embryogenesis, becoming defined as a distinctive region 10-15 days after pollination. The primary root is enclosed by a protective ensheathing structure, the coleorhiza. A variable number of adventitious lateral roots arise from the primary root (these are not formed during embryogenesis). See 'lateral root' for further information on lateral roots (seminal lateral roots). These lateral roots arise at varying points behind the zone of root hair formation on the primary root. The primary root is always present (except when killed by some injury e.g. freezing). Feldman , in Freeling & Walbot (eds) , The Maize Handbook , ID # 60920:< new dbxref> MaizeGDB:lv The seminal root system consists of the adventitious lateral roots which are present in the ungerminated caryopsis (kernel, seed) - they are formed during embryogenesis. The adventitious seminal lateral roots arise from 3 to 7 seminal root primordia. These primordia originate 30-40 days postanthesis, and emerge between the scutellum and the first internode. The adventitious seminal lateral root system, the primary root and its associated adventitious lateral roots, forms a small part of the total root system of the plant. These roots are of greatest importance during the early growth of the seedling before the adventitious crown roots of higher internodes become well established. zea_mays_anatomy seedling root system seminal lateral roots temporary roots ZEA:0015062 seminal root system ZEA:0015062 The seminal root system consists of the adventitious lateral roots which are present in the ungerminated caryopsis (kernel, seed) - they are formed during embryogenesis. The adventitious seminal lateral roots arise from 3 to 7 seminal root primordia. These primordia originate 30-40 days postanthesis, and emerge between the scutellum and the first internode. The adventitious seminal lateral root system, the primary root and its associated adventitious lateral roots, forms a small part of the total root system of the plant. These roots are of greatest importance during the early growth of the seedling before the adventitious crown roots of higher internodes become well established. Feldman in Freeling & Walbot (eds) , 1994. The Maize Handbook , ID # 60920:< new dbxref> Kiesselbach , ID # 59445:< new dbxref> MaizeGDB:lv Poethig in Sheridan , WF (ed) , 1982. Maize for Biological Research , ID # 25744:< new dbxref> The adventitious root system consists of all those roots that arise in the basal intercalary meristem of the lower internodes (above the first internode) of the culm (stem). The adventitious root system comprises the bulk of the lateral roots of the maize plant. There are two spatial components of the adventitious root system. 1. A subterranean (below-ground) origin; 2. An aerial (above-ground) origin. The subterranean adventitious roots are frequently called crown roots because they originate from the basal portion of the growing stem known as the crown. The first crown roots (4-5), arranged in a whorl, appear at the base of the second internode about as soon as the tip of the coleoptile reaches the soil surface. A few of the subsequent higher internodes may have a similar number of crown roots (in whorls), after which the successive internodes have more and larger crown roots up to 2-3 internodes above the soil surface. Note that the crown roots of the adventitious root system may appear to arise from the nodes of the culm but careful inspection will reveal their origin from the very base of the internode, frequently disrupting the leaf sheath tissue that arises from the node immediately below the whorl of crown roots. Those crown roots which are initially aerial in position relative to the soil surface are termed 'brace' or 'prop' roots. Until each prop root reaches the soil, it remains unbranched and relatively rigid, and is usually covered by a mucilaginous substance that protects the aerial part of the root from drying (dessication). Note that once the brace / prop roots enter the soil they produce numerous lateral adventitious roots (see 'root branches'). The subterranean crown roots produce numerous lateral adventitious roots early in their development. The crown roots arising from internodes 2 to approximately 5 tend to grow horizontally for some distance before turning downward. The crown roots from the base of the higher internodes (appearing later in the growing season) grow downward immediately after initiation. zea_mays_anatomy brace roots crown roots permanent roots prop roots ZEA:0015063 adventitious root system ZEA:0015063 The adventitious root system consists of all those roots that arise in the basal intercalary meristem of the lower internodes (above the first internode) of the culm (stem). The adventitious root system comprises the bulk of the lateral roots of the maize plant. There are two spatial components of the adventitious root system. 1. A subterranean (below-ground) origin; 2. An aerial (above-ground) origin. The subterranean adventitious roots are frequently called crown roots because they originate from the basal portion of the growing stem known as the crown. The first crown roots (4-5), arranged in a whorl, appear at the base of the second internode about as soon as the tip of the coleoptile reaches the soil surface. A few of the subsequent higher internodes may have a similar number of crown roots (in whorls), after which the successive internodes have more and larger crown roots up to 2-3 internodes above the soil surface. Note that the crown roots of the adventitious root system may appear to arise from the nodes of the culm but careful inspection will reveal their origin from the very base of the internode, frequently disrupting the leaf sheath tissue that arises from the node immediately below the whorl of crown roots. Those crown roots which are initially aerial in position relative to the soil surface are termed 'brace' or 'prop' roots. Until each prop root reaches the soil, it remains unbranched and relatively rigid, and is usually covered by a mucilaginous substance that protects the aerial part of the root from drying (dessication). Note that once the brace / prop roots enter the soil they produce numerous lateral adventitious roots (see 'root branches'). The subterranean crown roots produce numerous lateral adventitious roots early in their development. The crown roots arising from internodes 2 to approximately 5 tend to grow horizontally for some distance before turning downward. The crown roots from the base of the higher internodes (appearing later in the growing season) grow downward immediately after initiation. Feldman in Freeling & Walbot (eds) , 1994. The Maize Handbook , ID # 60920:< new dbxref> Kiesselbach , ID # 59445:< new dbxref> MaizeGDB:lv Poethig in Sheridan , WF (ed) , 1982. Maize for Biological Research , ID # 25744:< new dbxref> Some of the lateral roots of the maize plant comprise the seminal root system. These lateral roots are present in the ungerminated caryopsis (kernel, seed) - they are formed during embryogenesis. The seminal lateral roots arise from 3 to 7 seminal root primordia. These primordia originate 30-40 days post-anthesis, and emerge between the scutellum and the first internode. While these lateral roots comprise the seminal root system they are also part of the adventitious root system. zea_mays_anatomy ZEA:0015064 Re-defined lateral root & seminal lateral root & re-alligned their parentage to be more accurate. Still not sure about the relationship type for seminal lateral root (is it IS-A?). Same goes for seminal lateral root system relationship to adventitious root system - seems to be both IS-A & Part-Of ??? seminal lateral root ZEA:0015064 Some of the lateral roots of the maize plant comprise the seminal root system. These lateral roots are present in the ungerminated caryopsis (kernel, seed) - they are formed during embryogenesis. The seminal lateral roots arise from 3 to 7 seminal root primordia. These primordia originate 30-40 days post-anthesis, and emerge between the scutellum and the first internode. While these lateral roots comprise the seminal root system they are also part of the adventitious root system. Feldman in Freeling & Walbot (eds) , 1994. The Maize Handbook , ID # 60920:< new dbxref> Kiesselbach , ID # 59445:< new dbxref> MaizeGDB:lv Poethig in Sheridan , WF (ed) , 1982. Maize for Biological Research , ID # 25744:< new dbxref> These (adventitious) lateral roots emerge from the primary root (radicle, tap root) at varying points behind the zone of root hair formation. They originate from the pericycle. They are not present during embyogenesis. zea_mays_anatomy ZEA:0015065 lateral root ZEA:0015065 These (adventitious) lateral roots emerge from the primary root (radicle, tap root) at varying points behind the zone of root hair formation. They originate from the pericycle. They are not present during embyogenesis. Feldman in Freeling & Walbot (eds) , 1994. The Maize Handbook , ID # 60920:< new dbxref> MaizeGDB:lv Poethig in Sheridan , WF (ed) , 1982. Maize for Biological Research , ID # 25744:< new dbxref> There are two spatial components of the adventitious root system. 1. A subterranean (below-ground) origin; 2. An aerial (above-ground) origin. The subterranean adventitious roots are frequently called crown roots because they originate from the basal portion of the growing stem known as the crown. The first crown roots (4-5), arranged in a whorl, appear at the base of the second internode about as soon as the tip of the coleoptile reaches the soil surface. A few of the subsequent higher internodes may have a similar number of crown roots (in whorls), after which the successive internodes have more and larger crown roots up to 2-3 internodes above the soil surface. Note that the crown roots of the adventitious root system may appear to arise from the nodes of the culm but careful inspection will reveal their origin from the very base of the internode, frequently disrupting the leaf sheath tissue that arises from the node immediately below the whorl of crown roots. Those crown roots which are initially aerial in position relative to the soil surface are termed 'brace' or 'prop' roots. Until each prop root reaches the soil, it remains unbranched and relatively rigid, and is usually covered by a mucilaginous substance that protects the aerial part of the root from drying (desiccation). Note that once the brace / prop roots enter the soil they produce numerous lateral adventitious roots (see 'root branches'). The subterranean crown roots produce numerous lateral adventitious roots early in their development. The crown roots arising from internodes 2 to approximately 5 tend to grow horizontally for some distance before turning downward. The crown roots from the base of the higher internodes (appearing later in the growing season) grow downward immediately after initiation. zea_mays_anatomy ZEA:0015066 crown roots ZEA:0015066 There are two spatial components of the adventitious root system. 1. A subterranean (below-ground) origin; 2. An aerial (above-ground) origin. The subterranean adventitious roots are frequently called crown roots because they originate from the basal portion of the growing stem known as the crown. The first crown roots (4-5), arranged in a whorl, appear at the base of the second internode about as soon as the tip of the coleoptile reaches the soil surface. A few of the subsequent higher internodes may have a similar number of crown roots (in whorls), after which the successive internodes have more and larger crown roots up to 2-3 internodes above the soil surface. Note that the crown roots of the adventitious root system may appear to arise from the nodes of the culm but careful inspection will reveal their origin from the very base of the internode, frequently disrupting the leaf sheath tissue that arises from the node immediately below the whorl of crown roots. Those crown roots which are initially aerial in position relative to the soil surface are termed 'brace' or 'prop' roots. Until each prop root reaches the soil, it remains unbranched and relatively rigid, and is usually covered by a mucilaginous substance that protects the aerial part of the root from drying (desiccation). Note that once the brace / prop roots enter the soil they produce numerous lateral adventitious roots (see 'root branches'). The subterranean crown roots produce numerous lateral adventitious roots early in their development. The crown roots arising from internodes 2 to approximately 5 tend to grow horizontally for some distance before turning downward. The crown roots from the base of the higher internodes (appearing later in the growing season) grow downward immediately after initiation. MaizeGDB:lv The subterranean crown roots are a component of the adventitious root system. They are termed crown roots because they originate from the basal portion of the growing stem known as the crown. The first subterranean crown roots (4-5), arranged in a whorl, appear at the base of the second internode about as soon as the tip of the coleoptile reaches the soil surface. A few of the subsequent higher internodes may have a similar number of crown roots (in whorls), after which the successive internodes have more and larger crown roots up to 2-3 internodes above the soil surface. Note that the crown roots above the soil surface (aerial) are frequently called 'brace' or 'prop' roots. The crown roots emerge from the extreme base of the internode. The subterranean crown roots produce numerous lateral adventitious roots (see 'root branches') early in their development. The crown roots arising from internodes 2 to approximately 5 tend to grow horizontally for some distance before turning downward. The crown roots from the base of the higher internodes (appearing later in the growing season) grow downward immediately after initiation. zea_mays_anatomy permanent roots ZEA:0015067 subterranean crown roots ZEA:0015067 The subterranean crown roots are a component of the adventitious root system. They are termed crown roots because they originate from the basal portion of the growing stem known as the crown. The first subterranean crown roots (4-5), arranged in a whorl, appear at the base of the second internode about as soon as the tip of the coleoptile reaches the soil surface. A few of the subsequent higher internodes may have a similar number of crown roots (in whorls), after which the successive internodes have more and larger crown roots up to 2-3 internodes above the soil surface. Note that the crown roots above the soil surface (aerial) are frequently called 'brace' or 'prop' roots. The crown roots emerge from the extreme base of the internode. The subterranean crown roots produce numerous lateral adventitious roots (see 'root branches') early in their development. The crown roots arising from internodes 2 to approximately 5 tend to grow horizontally for some distance before turning downward. The crown roots from the base of the higher internodes (appearing later in the growing season) grow downward immediately after initiation. Feldman in Freeling & Walbot (eds) , 1994. The Maize Handbook , ID # 60920:< new dbxref> Kiesselbach , ID # 59445:< new dbxref> MaizeGDB:lv Poethig in Sheridan , WF (ed) , 1982. Maize for Biological Research , ID # 25744:< new dbxref> Prop ('brace') roots are crown roots which have an aerial (above-ground) origin. They emerge from the extreme basal portion of 2-3 internodes above the soil surface. Their emergence frequently disrupts the leaf sheath tissue that arises from the node immediately below the whorl of prop crown roots. Until each prop root reaches the soil, it remains unbranched and relatively rigid, and is usually covered by a mucilaginous substance that protects the aerial part of the root from drying (dessication). Note that once the prop / brace roots enter the soil they produce numerous lateral adventitious roots (see 'root branches'). The crown roots arising from internodes 2 to approximately 5 tend to grow horizontally for some distance before turning downward. The crown roots from the base of the higher internodes (appearing later in the growing season) grow downward immediately after initiation. zea_mays_anatomy brace roots ZEA:0015068 prop roots ZEA:0015068 Prop ('brace') roots are crown roots which have an aerial (above-ground) origin. They emerge from the extreme basal portion of 2-3 internodes above the soil surface. Their emergence frequently disrupts the leaf sheath tissue that arises from the node immediately below the whorl of prop crown roots. Until each prop root reaches the soil, it remains unbranched and relatively rigid, and is usually covered by a mucilaginous substance that protects the aerial part of the root from drying (dessication). Note that once the prop / brace roots enter the soil they produce numerous lateral adventitious roots (see 'root branches'). The crown roots arising from internodes 2 to approximately 5 tend to grow horizontally for some distance before turning downward. The crown roots from the base of the higher internodes (appearing later in the growing season) grow downward immediately after initiation. Feldman in Freeling & Walbot (eds) , 1994. The Maize Handbook , ID # 60920:< new dbxref> Kiesselbach , ID # 59445:< new dbxref> MaizeGDB:lv Poethig in Sheridan , WF (ed) , 1982. Maize for Biological Research , ID # 25744:< new dbxref> A root branch is an adventitious root that emerges from any of the various types of lateral root. Root branches arise at varying points behind (posterior to) the zone of root hair formation on the primary root. Root branches emerge from the surface of the main roots (the various types of lateral roots) at irregular intervals. When a root branches, the initial of each branch is formed from cells of the pericycle. Via cell division a bulging hemispherical mass of meristematic tissue is formed. The outer part of this forms the beginning of the rootcap, while the cells of the growing point are near the flat basal part of the hemispherical mass. During elongation the new root branch is forced through the adjoining tissues of the cortex of the originating root and emerges at the surface. As the xylem and phloem tissues are differentiated in the root branch they become joined to those of the originating root. zea_mays_anatomy ZEA:0015069 root branch ZEA:0015069 A root branch is an adventitious root that emerges from any of the various types of lateral root. Root branches arise at varying points behind (posterior to) the zone of root hair formation on the primary root. Root branches emerge from the surface of the main roots (the various types of lateral roots) at irregular intervals. When a root branches, the initial of each branch is formed from cells of the pericycle. Via cell division a bulging hemispherical mass of meristematic tissue is formed. The outer part of this forms the beginning of the rootcap, while the cells of the growing point are near the flat basal part of the hemispherical mass. During elongation the new root branch is forced through the adjoining tissues of the cortex of the originating root and emerges at the surface. As the xylem and phloem tissues are differentiated in the root branch they become joined to those of the originating root. Kiesselbach , ID # 59445:< new dbxref> MaizeGDB:lv The lateral branch internode is the region of the lateral branch which is bounded by a lateral branch node at each end. Lateral branch internodes are an integral part of the structure of the lateral branches (ear shoots). Lateral branch internodes are not biologically homologous with culm internodes, although they are colloquially referred to as 'internodes'. Notwithstanding this non-homology, the general anatomical structure of a typical internode consists of the following: a pithy interior comprised mainly of parenchyma with vascular bundles distributed throughout (as is typical of monocot stem vascular anatomy). In cross section (transverse section) the epidermis is the outer single layer of cells. The walls of the epidermal cells are considerably thickened, lignified and silicified. Immediately below the epidermis is a layer of sclerenchyma which varies from 1-10 cells in thickness. This sclerenchyma tissue does not form a continuous band underneath the epidermis but forms longitudinal bands or strips around the peripheral vascular bundles, alternating with strips of parenchyma beneath the rows of stomata. Within this discontinuous band of sclerenchyma are several rows of vascular bundles, each surrounded by a large amount of sclerenchyma. The peripheral bundles are smaller and are spaced much closer than those in the central part of the internode (in cross section) and are separated from each other and from the peripheral sclerenchyma by narrow tracts of parenchyma. The non-peripheral vascular bundles are surrounded by a bundle sheath, the cells of which are lignified and sclerenchymatous. The sclerenchymatous bundle sheath is much more developed opposite the phloem and xylem of each vascular bundle, forming phloem and xylem caps. maizedb:XXXXX zea_mays_anatomy ear shoot internode internode ZEA:0015070 lateral branch internode ZEA:0015070 The lateral branch internode is the region of the lateral branch which is bounded by a lateral branch node at each end. Lateral branch internodes are an integral part of the structure of the lateral branches (ear shoots). Lateral branch internodes are not biologically homologous with culm internodes, although they are colloquially referred to as 'internodes'. Notwithstanding this non-homology, the general anatomical structure of a typical internode consists of the following: a pithy interior comprised mainly of parenchyma with vascular bundles distributed throughout (as is typical of monocot stem vascular anatomy). In cross section (transverse section) the epidermis is the outer single layer of cells. The walls of the epidermal cells are considerably thickened, lignified and silicified. Immediately below the epidermis is a layer of sclerenchyma which varies from 1-10 cells in thickness. This sclerenchyma tissue does not form a continuous band underneath the epidermis but forms longitudinal bands or strips around the peripheral vascular bundles, alternating with strips of parenchyma beneath the rows of stomata. Within this discontinuous band of sclerenchyma are several rows of vascular bundles, each surrounded by a large amount of sclerenchyma. The peripheral bundles are smaller and are spaced much closer than those in the central part of the internode (in cross section) and are separated from each other and from the peripheral sclerenchyma by narrow tracts of parenchyma. The non-peripheral vascular bundles are surrounded by a bundle sheath, the cells of which are lignified and sclerenchymatous. The sclerenchymatous bundle sheath is much more developed opposite the phloem and xylem of each vascular bundle, forming phloem and xylem caps. MaizeGDB:lv (ID # 165572) a lateral branch axillary (lateral) bud is found in the axil of each of the husk leaves and the prophyll, which arise from the lateral branch nodes of the shank (proximal end of the lateral (axillary) branch(es)). All of the lateral branch axillary buds remain dormant throughout the life-span of the Zea mays plant. maizedb:pldv (ID#165572) zea_mays_anatomy axillary bud ZEA:0015071 lateral branch axillary bud ZEA:0015071 a lateral branch axillary (lateral) bud is found in the axil of each of the husk leaves and the prophyll, which arise from the lateral branch nodes of the shank (proximal end of the lateral (axillary) branch(es)). All of the lateral branch axillary buds remain dormant throughout the life-span of the Zea mays plant. MaizeGDB:59445 MaizeGDB:60893 MaizeGDB:lv (ID # 165572) the culm is equivalent to the stalk of the Zea mays plant. zea_mays_anatomy ZEA:0015072 culm ZEA:0015072 the culm is equivalent to the stalk of the Zea mays plant. MaizeGDB:58047 A lateral branch (often referred to as an ear shoot) of the corn plant bears the female inflorescence (flowering system). Each lateral branch arises from the development of a lateral (axillary) bud, adjacent to one of the nodes of the culm. The lateral branch is subtended by a leaf. After pollination via the silks and fertilization of the ovule within each functionally female floret, the lateral branch develops into the typical ear. The lateral branch arises from the culm (main stem/stalk) at a node. The portion of the lateral branch below the 'ear' is called the shank. The axillary buds arising from nodes above the soil surface terminate in a pistillate inflorescence (ear). Usually all soon degenerate except the upper one or two located about midway up the culm. The amount of growth before disintegration (senescence) varies as the axillary buds may either die without much development or form 'ears' several centimeters long which resemble the functional ears, until they senesce. maizedb:pldv (ID#165572 maizedb:pldv (ID#165572) zea_mays_anatomy axillary branch ear shoot ZEA:0015073 lateral branch ZEA:0015073 A lateral branch (often referred to as an ear shoot) of the corn plant bears the female inflorescence (flowering system). Each lateral branch arises from the development of a lateral (axillary) bud, adjacent to one of the nodes of the culm. The lateral branch is subtended by a leaf. After pollination via the silks and fertilization of the ovule within each functionally female floret, the lateral branch develops into the typical ear. The lateral branch arises from the culm (main stem/stalk) at a node. The portion of the lateral branch below the 'ear' is called the shank. The axillary buds arising from nodes above the soil surface terminate in a pistillate inflorescence (ear). Usually all soon degenerate except the upper one or two located about midway up the culm. The amount of growth before disintegration (senescence) varies as the axillary buds may either die without much development or form 'ears' several centimeters long which resemble the functional ears, until they senesce. MaizeGDB:232442 MaizeGDB:59445 MaizeGDB:lv (ID # 165572) The shank is the portion of the lateral branch below the ear. 8-14 modified leaves, called husks, are arranged up the shank in an alternate pattern and surround the developing ear. The basal husk leaf is termed the prophyll and is not homologous with the other husk leaves. Each husk leaf arises from a node along the length of the lateral branch. A dormant lateral (axillary) bud is found in the axil of each husk leaf. zea_mays_anatomy ZEA:0015074 shank ZEA:0015074 The shank is the portion of the lateral branch below the ear. 8-14 modified leaves, called husks, are arranged up the shank in an alternate pattern and surround the developing ear. The basal husk leaf is termed the prophyll and is not homologous with the other husk leaves. Each husk leaf arises from a node along the length of the lateral branch. A dormant lateral (axillary) bud is found in the axil of each husk leaf. MaizeGDB:165572 MaizeGDB:232442 The central axis/core of the 'ear' (distal end of the lateral branch/ear shoot) upon which the kernels (caryopses) are borne. The cob is similar to the central spike of the tassel (male inflorescence) in that it produces multiple rows of paired spikelets (polystichous phyllotaxy). ZEA:0015084 maizedb:59445 (p. 53) zea_mays_anatomy rachis ZEA:0015075 cob ZEA:0015075 The central axis/core of the 'ear' (distal end of the lateral branch/ear shoot) upon which the kernels (caryopses) are borne. The cob is similar to the central spike of the tassel (male inflorescence) in that it produces multiple rows of paired spikelets (polystichous phyllotaxy). MaizeGDB:165572 MaizeGDB:60893 The culm nodes are regions of dense tissue appearing as slightly swollen regions along the length of the culm. The culms of typical eastern Nebraska corn plants consist of about 24 culm nodes (alternating with culm internodes). The number of culm nodes may vary according to regional type and environmental effects. Approximately 8 culm internodes remain very short (contracted) and subterranean, forming an inverted cone-shaped basal end of the culm (stem) known as the crown. Culm nodes are an integral part of the structure of the culm (stalk). Culm nodes are not biologically homologous with lateral branch nodes, although they are colloquially referred to as 'nodes'. Notwithstanding this non-homology, the general anatomical structure of a typical node consists of the following: the structure of nodes is more complicated than that of the internodes due to the branching and cross connections between the vascular bundles forming the nodal complex. The vascular bundles with their cross connections fill up most of the space of the node, so there is relatively little parenchyma. In the zone of leaf attachment at the culm nodes, the epidermis of the adjacent culm internodes becomes continuous over the attached leaf sheath. Not much elongation occurs in the culm nodes and no protoxylem lacunae are formed. The arrangement of the tissues in the vascular bundles is more irregular and no bundle caps are formed in the endosperm adjacent to the vascular tissue. As the vascular bundles enter a culm node from below, they enlarge in diameter and form cross connections, creating a tangled network which extends for several millimeters up into the adjacent internode. Many of the vascular bundles branch as they pass through the culm node, while some turn abruptly sideways for a short distance. Some vascular bundles pass from the culm node into the base of the leaf sheath. maizedb:64470 zea_mays_anatomy node ZEA:0015076 culm node ZEA:0015076 The culm nodes are regions of dense tissue appearing as slightly swollen regions along the length of the culm. The culms of typical eastern Nebraska corn plants consist of about 24 culm nodes (alternating with culm internodes). The number of culm nodes may vary according to regional type and environmental effects. Approximately 8 culm internodes remain very short (contracted) and subterranean, forming an inverted cone-shaped basal end of the culm (stem) known as the crown. Culm nodes are an integral part of the structure of the culm (stalk). Culm nodes are not biologically homologous with lateral branch nodes, although they are colloquially referred to as 'nodes'. Notwithstanding this non-homology, the general anatomical structure of a typical node consists of the following: the structure of nodes is more complicated than that of the internodes due to the branching and cross connections between the vascular bundles forming the nodal complex. The vascular bundles with their cross connections fill up most of the space of the node, so there is relatively little parenchyma. In the zone of leaf attachment at the culm nodes, the epidermis of the adjacent culm internodes becomes continuous over the attached leaf sheath. Not much elongation occurs in the culm nodes and no protoxylem lacunae are formed. The arrangement of the tissues in the vascular bundles is more irregular and no bundle caps are formed in the endosperm adjacent to the vascular tissue. As the vascular bundles enter a culm node from below, they enlarge in diameter and form cross connections, creating a tangled network which extends for several millimeters up into the adjacent internode. Many of the vascular bundles branch as they pass through the culm node, while some turn abruptly sideways for a short distance. Some vascular bundles pass from the culm node into the base of the leaf sheath. MaizeGDB:59445 MaizeGDB:lv (ID # 165572) The lowermost leaf on the short lateral (axillary) branch (shank) bearing the ear. The prophyll arises from the lateral (axillary) branch from the most proximal node and is positioned adjacent to the internode of the main culm. The prophyll is distinct from the husk leaves (non-homologous) in having two apices and two distinct midribs (keels; bikeeled). zea_mays_anatomy ZEA:0015077 prophyll ZEA:0015077 The lowermost leaf on the short lateral (axillary) branch (shank) bearing the ear. The prophyll arises from the lateral (axillary) branch from the most proximal node and is positioned adjacent to the internode of the main culm. The prophyll is distinct from the husk leaves (non-homologous) in having two apices and two distinct midribs (keels; bikeeled). MaizeGDB:Clayton & Renvoiz ref ID # MaizeGDB:lv (ID # 165572) The husks are modified leaves which arise from the short lateral (axillary) branch (shank) bearing the ear. They surround the developing ear. The lower (outer) husks are arranged in a distichous pattern (opposite rows and alternate occurrence, like the foliar leaves) while the upper (inner) husks are polystichous in arrangement. Husks are considered to be somewhat homologous with the adult and juvenile leaves (foliar leaves). Vestiges of the ligular region and lamina (husk leaf, flag leaf) of the husk may be present. Some strains of maize (Zea mays) (e.g. sweet corn) produce husks with a prominent ligule and husk leaf (lamina), which are sometimes called "flag leaves". Husks are relatively thin and flat, unlike the adult and juvenile foliar leaves. The sheaths of the husks are much broader and thinner than the sheaths of the foliar (ordinary) leaves. The venation lacks the presence of a distinct midvein, while lateral veins predominate throughout the husk. Each husk is attached to a unique lateral branch node on the shank (growing lateral (axillary) branch) of the ear. The lowermost husk on the shank, between the shank and the adjacent internode of the main culm, is a prophyll (ZEA:15077). It is easily confused as being a husk but the prophyll is not homologous with a husk. Note that the term husk is colloquially used for the modified leaf tissue which surrounds the ear and the term is seldom associated with husk ligule and husk leaf (flag leaf). However, botanically, the term husk should be used for the entire structure (fide Kiesselbach, 1949), comprising the husk sheath, husk ligule and husk leaf (the latter components frequently being very diminutive). The perspective that husks are somewhat homologous with the adult and juvenile leaves justifies the usage of the term husk sheath for the predominant portion of the husk which surrounds the ear. zea_mays_anatomy ZEA:0015078 husk ZEA:0015078 The husks are modified leaves which arise from the short lateral (axillary) branch (shank) bearing the ear. They surround the developing ear. The lower (outer) husks are arranged in a distichous pattern (opposite rows and alternate occurrence, like the foliar leaves) while the upper (inner) husks are polystichous in arrangement. Husks are considered to be somewhat homologous with the adult and juvenile leaves (foliar leaves). Vestiges of the ligular region and lamina (husk leaf, flag leaf) of the husk may be present. Some strains of maize (Zea mays) (e.g. sweet corn) produce husks with a prominent ligule and husk leaf (lamina), which are sometimes called "flag leaves". Husks are relatively thin and flat, unlike the adult and juvenile foliar leaves. The sheaths of the husks are much broader and thinner than the sheaths of the foliar (ordinary) leaves. The venation lacks the presence of a distinct midvein, while lateral veins predominate throughout the husk. Each husk is attached to a unique lateral branch node on the shank (growing lateral (axillary) branch) of the ear. The lowermost husk on the shank, between the shank and the adjacent internode of the main culm, is a prophyll (ZEA:15077). It is easily confused as being a husk but the prophyll is not homologous with a husk. Note that the term husk is colloquially used for the modified leaf tissue which surrounds the ear and the term is seldom associated with husk ligule and husk leaf (flag leaf). However, botanically, the term husk should be used for the entire structure (fide Kiesselbach, 1949), comprising the husk sheath, husk ligule and husk leaf (the latter components frequently being very diminutive). The perspective that husks are somewhat homologous with the adult and juvenile leaves justifies the usage of the term husk sheath for the predominant portion of the husk which surrounds the ear. MaizeGDB:Clayton & Renvoize ref ID # MaizeGDB:kiesselbach (ID# 59445) MaizeGDB:lv (ID # 165572) http://www.harcourt.com/dictionary/def/4/9/6/3/4963600.html The culm internode is the region of the culm which is bounded by a culm node at each end. Culm internodes are an integral part of the structure of the culm. Typically the culm internodes are considered homologous with lateral branch internodes of the lateral branches (ear shoots). However, these two types of internodes are biologically distinct (non-homologous). Notwithstanding this non-homology, the general anatomical structure of a typical internode consists of the following: a pithy interior comprised mainly of parenchyma with vascular bundles distributed throughout (as is typical of monocot stem vascular anatomy). In cross section (transverse section) the epidermis is the outer single layer of cells. The walls of the epidermal cells are considerably thickened, lignified and silicified. Stomata are present in the epidermis but are less abundant than in the epidermis of leaves. Immediately below the epidermis is a layer of sclerenchyma which varies from 1-10 cells in thickness. This sclerenchyma tissue does not form a continuous band underneath the epidermis but forms longitudinal bands or strips around the peripheral vascular bundles, alternating with strips of parenchyma beneath the rows of stomata. Within this discontinuous band of sclerenchyma are several rows of vascular bundles, each surrounded by a large amount of sclerenchyma. The peripheral bundles are smaller and are spaced much closer than those in the central part of the internode (in cross section) and are separated from each other and from the peripheral sclerenchyma by narrow tracts of parenchyma. The non-peripheral vascular bundles are surrounded by a bundle sheath, the cells of which are lignified and sclerenchymatous. The sclerenchymatous bundle sheath is much more developed opposite the phloem and xylem of each vascular bundle, forming phloem and xylem caps. maizedb:XXXXX zea_mays_anatomy internode ZEA:0015079 culm internode ZEA:0015079 The culm internode is the region of the culm which is bounded by a culm node at each end. Culm internodes are an integral part of the structure of the culm. Typically the culm internodes are considered homologous with lateral branch internodes of the lateral branches (ear shoots). However, these two types of internodes are biologically distinct (non-homologous). Notwithstanding this non-homology, the general anatomical structure of a typical internode consists of the following: a pithy interior comprised mainly of parenchyma with vascular bundles distributed throughout (as is typical of monocot stem vascular anatomy). In cross section (transverse section) the epidermis is the outer single layer of cells. The walls of the epidermal cells are considerably thickened, lignified and silicified. Stomata are present in the epidermis but are less abundant than in the epidermis of leaves. Immediately below the epidermis is a layer of sclerenchyma which varies from 1-10 cells in thickness. This sclerenchyma tissue does not form a continuous band underneath the epidermis but forms longitudinal bands or strips around the peripheral vascular bundles, alternating with strips of parenchyma beneath the rows of stomata. Within this discontinuous band of sclerenchyma are several rows of vascular bundles, each surrounded by a large amount of sclerenchyma. The peripheral bundles are smaller and are spaced much closer than those in the central part of the internode (in cross section) and are separated from each other and from the peripheral sclerenchyma by narrow tracts of parenchyma. The non-peripheral vascular bundles are surrounded by a bundle sheath, the cells of which are lignified and sclerenchymatous. The sclerenchymatous bundle sheath is much more developed opposite the phloem and xylem of each vascular bundle, forming phloem and xylem caps. MaizeGDB:59445 MaizeGDB:lv (ID # 165572) The lateral branch nodes are regions of dense tissue appearing as slightly swollen regions along the length of the lateral branch. Lateral branch nodes are an integral part of the structure of the lateral branchs (ear shoots). Lateral branch internodes are not biologically homologous with culm nodes, although they are colloquially referred to as 'nodes'. Notwithstanding this non-homology, the general anatomical structure of a typical node consists of the following: the structure of nodes is more complicated than that of the internodes due to the branching and cross connections between the vascular bundles forming the nodal complex. The vascular bundles with their cross connections fill up most of the space of the node, so there is relatively little parenchyma. In the zone of husk and prophyll attachment at the lateral branch nodes, the epidermis of the adjacent lateral branch internodes becomes continuous over the prophyll and husk. Not much elongation occurs in the lateral branch nodes and no protoxylem lacunae are formed. The arrangement of the tissues in the vascular bundles is more irregular and no bundle caps are formed in the endosperm adjacent to the vascular tissue. As the vascular bundles enter a lateral branch node from below, they enlarge in diameter and form cross connections, creating a tangled network which extends for several millimeters along the length of the lateral branch. Many of the vascular bundles branch as they pass through the lateral branch node, while some turn abruptly sideways for a short distance. Some vascular bundles pass from the lateral branch node into the base of the prophyll of the sheathing base of the husk leaf. maizedb:XXXXX zea_mays_anatomy ear shoot node node ZEA:0015080 lateral branch node ZEA:0015080 The lateral branch nodes are regions of dense tissue appearing as slightly swollen regions along the length of the lateral branch. Lateral branch nodes are an integral part of the structure of the lateral branchs (ear shoots). Lateral branch internodes are not biologically homologous with culm nodes, although they are colloquially referred to as 'nodes'. Notwithstanding this non-homology, the general anatomical structure of a typical node consists of the following: the structure of nodes is more complicated than that of the internodes due to the branching and cross connections between the vascular bundles forming the nodal complex. The vascular bundles with their cross connections fill up most of the space of the node, so there is relatively little parenchyma. In the zone of husk and prophyll attachment at the lateral branch nodes, the epidermis of the adjacent lateral branch internodes becomes continuous over the prophyll and husk. Not much elongation occurs in the lateral branch nodes and no protoxylem lacunae are formed. The arrangement of the tissues in the vascular bundles is more irregular and no bundle caps are formed in the endosperm adjacent to the vascular tissue. As the vascular bundles enter a lateral branch node from below, they enlarge in diameter and form cross connections, creating a tangled network which extends for several millimeters along the length of the lateral branch. Many of the vascular bundles branch as they pass through the lateral branch node, while some turn abruptly sideways for a short distance. Some vascular bundles pass from the lateral branch node into the base of the prophyll of the sheathing base of the husk leaf. MaizeGDB:59445 MaizeGDB:lv (ID # 165572) A culm axillary (lateral) bud is found in the axil of each leaf arising from the culm nodes. Most of the culm axillary buds remain dormant throughout the life-span of the Zea mays plant. It is usual for only the upper two culm axillary buds to each develop into a lateral branch bearing an ear (pistillate inflorescence). maizedb:XXXXX zea_mays_anatomy axillary bud lateral bud ZEA:0015081 culm axillary bud ZEA:0015081 A culm axillary (lateral) bud is found in the axil of each leaf arising from the culm nodes. Most of the culm axillary buds remain dormant throughout the life-span of the Zea mays plant. It is usual for only the upper two culm axillary buds to each develop into a lateral branch bearing an ear (pistillate inflorescence). MaizeGDB:59445 MaizeGDB:60893 MaizeGDB:lv (ID # 165572) The mesocotyl is the first culm internode of the maize culm. The mesocotyl is the culm internode below the plumule, between the coleoptile node and the scutellar node. This first culm internode is a very characteristic and unique feature of the Poaceae (alt. Gramineae). The first culm internode is frequently termed the 'mesocotyl' in the literature. This first culm internode is not evident 15 days after pollination, when the coleoptile node is virtually in contact with the scutellar node. Subsequent intercalary growth results in considerable lengthening of the first culm internode (mesocotyl) in the embryo. "The internode between the scutellar node and coeoptile in the embryo and seedling of Poaceae" (K. Esau. 1977. The Anatomy of Seed Plants, John Wiley & Sons) zea_mays_anatomy ZEA:0015082 mesocotyl ZEA:0015082 The mesocotyl is the first culm internode of the maize culm. The mesocotyl is the culm internode below the plumule, between the coleoptile node and the scutellar node. This first culm internode is a very characteristic and unique feature of the Poaceae (alt. Gramineae). The first culm internode is frequently termed the 'mesocotyl' in the literature. This first culm internode is not evident 15 days after pollination, when the coleoptile node is virtually in contact with the scutellar node. Subsequent intercalary growth results in considerable lengthening of the first culm internode (mesocotyl) in the embryo. "The internode between the scutellar node and coeoptile in the embryo and seedling of Poaceae" (K. Esau. 1977. The Anatomy of Seed Plants, John Wiley & Sons) MaizeGDB:208059 MaizeGDB:lv (ID # 165572) The attachment of the leaf to the node of the culm is via the base of the leaf sheath. The attachment of the leaf base is not in a circle but in a short spiral extending a little more than once around the culm (stem). The edge of the leaf which is attached lower on the culm (at a node) overlaps the other edge of the leaf which is attached to the culm slightly higher up. Note that the pattern of overlap alternates between successive leaves - each leaf sheath is rolled around the culm in the opposite direction from that of the preceding leaf. zea_mays_anatomy ZEA:0015083 leaf base attachment ZEA:0015083 The attachment of the leaf to the node of the culm is via the base of the leaf sheath. The attachment of the leaf base is not in a circle but in a short spiral extending a little more than once around the culm (stem). The edge of the leaf which is attached lower on the culm (at a node) overlaps the other edge of the leaf which is attached to the culm slightly higher up. Note that the pattern of overlap alternates between successive leaves - each leaf sheath is rolled around the culm in the opposite direction from that of the preceding leaf. MaizeGDB:59445 MaizeGDB:lv (ID # 165572) The 'ear' is the distal part of a lateral (axillary) branch and bears the functionally-female florets in a highly contracted inflorescence. The upper one or two culm axillary buds (associated with the nodes of the culm (stalk)), located about midway on the culm, develop fully into short lateral branches, each terminating in a developing ear capable of producing mature kernels (caryopses). Each of the culm axillary buds is covered with about 8-14 modified leaves called husks, and a prophyll (the most basal modified leaf on the lateral branch). The ear branch (lateral branch, shank) consists of nodes and short internodes. The ear itself does not have lateral branches but its thick axis (called the cob), is similar to the central spike of the tassel in that it produces multiple longitudinal rows of paired spikelets (polystichous phyllotaxy). Each spikelet is ensheathed (enclosed) by a pair of glumes and contains only one functionally-female floret. Although two florets are initiated during spikelet ontogeny, only the upper floret develops; the lower floret aborts at an early stage of development. Both florets within a spikelet produce a lemma, but usually only the upper floret produces a palea. The palea of the lower floret either does not initiate or remains rudimentary. Each functionally-female floret produces an ovary with an elongated silk (style) covered with hairs (trichomes). Note that the culm axillary buds, which are not appropriately placed for full development, degenerate at an early stage. The amount of growth before degeneration/senescence occurs varies, as the buds may either die without much development or form ears several centimeters long, which resemble the functional ears until they senesce (die). From a perspective of developmental biology the ear is initially smooth. But numerous outgrowths (primordia) typically soon appear (in an acropetal direction) which become two lobed (spikelet pair primordium), each lobe finally giving rise to a spikelet (the basic definitive structure of the grass inflorescence) with two florets (flowers). The two glumes, which arise from the pedicel of each spikelet, subtend and ensheath each spikelet and are formed in the same manner as the vegetative leaves. The glume initials emanate from the tissue of the spikelet primordium during the ontogeny of the spikelet. Note that Zea mays is monoecious (separate male & female flowers/florets are found on the same plant). The growth of the ear (pistillate inflorescence) is indeterminate. (Kiesselbach, ID#59445, Cheng & Pareddy, ID#60893, Vincent, ID#165572) maizedb:pldv (ID#165572) zea_mays_anatomy pistillate inflorescence ZEA:0015084 ear (functionally female inflorescence) ZEA:0015084 The 'ear' is the distal part of a lateral (axillary) branch and bears the functionally-female florets in a highly contracted inflorescence. The upper one or two culm axillary buds (associated with the nodes of the culm (stalk)), located about midway on the culm, develop fully into short lateral branches, each terminating in a developing ear capable of producing mature kernels (caryopses). Each of the culm axillary buds is covered with about 8-14 modified leaves called husks, and a prophyll (the most basal modified leaf on the lateral branch). The ear branch (lateral branch, shank) consists of nodes and short internodes. The ear itself does not have lateral branches but its thick axis (called the cob), is similar to the central spike of the tassel in that it produces multiple longitudinal rows of paired spikelets (polystichous phyllotaxy). Each spikelet is ensheathed (enclosed) by a pair of glumes and contains only one functionally-female floret. Although two florets are initiated during spikelet ontogeny, only the upper floret develops; the lower floret aborts at an early stage of development. Both florets within a spikelet produce a lemma, but usually only the upper floret produces a palea. The palea of the lower floret either does not initiate or remains rudimentary. Each functionally-female floret produces an ovary with an elongated silk (style) covered with hairs (trichomes). Note that the culm axillary buds, which are not appropriately placed for full development, degenerate at an early stage. The amount of growth before degeneration/senescence occurs varies, as the buds may either die without much development or form ears several centimeters long, which resemble the functional ears until they senesce (die). From a perspective of developmental biology the ear is initially smooth. But numerous outgrowths (primordia) typically soon appear (in an acropetal direction) which become two lobed (spikelet pair primordium), each lobe finally giving rise to a spikelet (the basic definitive structure of the grass inflorescence) with two florets (flowers). The two glumes, which arise from the pedicel of each spikelet, subtend and ensheath each spikelet and are formed in the same manner as the vegetative leaves. The glume initials emanate from the tissue of the spikelet primordium during the ontogeny of the spikelet. Note that Zea mays is monoecious (separate male & female flowers/florets are found on the same plant). The growth of the ear (pistillate inflorescence) is indeterminate. (Kiesselbach, ID#59445, Cheng & Pareddy, ID#60893, Vincent, ID#165572) MaizeGDB:59445 MaizeGDB:60893 MaizeGDB:lv (ID # 165572) The functionally-male flowering structure (staminate inflorescence) which terminates the culm (stem) of a Zea mays plant. The tassel is a branched inflorescence and consists of a central spike (rachis) and about 10-50 lateral branches. Many paired spikelets (pedicellate & sessile) arise from the central spike and lateral branches. The paired spikelets on the central spike occur in many ranks (longitudinal rows) around the central spike. The paired spikelets of the lateral branches are arranged in only two rows on the lower (adaxial) surface of each lateral branch. Each spikelet bears two male (staminate) florets, the upper and the lower floret. The development of the upper floret is about 2-3 days ahead of the lower floret (measured at anthesis). Each spikelet has a pair of leaf-like (bract-like) glumes, arising from the spikelet pedicel, which ensheath (encase) the two florets within. Within the glumes each floret is further enclosed by a pair of thin scale-like bracts - the lemma (located adjacent to the glume) and a palea (located opposite to the lemma and adjacent to the palea of the other floret in the spikelet). Within each floret, two of the three stamens are located adjacent to the margins of the palea; the third stamen is located adjacent to the midline of the lemma and is flanked by two lodicules. The two lodicules swell at the commencement of anthesis (period from floret opening to fertilization). This swelling forces apart the lemma and palea enclosing the floret, which facilitates the extrusion of the anthers via the elongation of the filaments. Following extrusion, the anthers dangle downward and shed pollen from an opening at the apex (tip) of each anther locule. The tassel exhibits an indeterminate growth pattern. Note that Zea mays is monoecious (separate male & female flowers/florets borne on the same plant). From a perspective of developmental biology the central axis and lateral branches of the tassel are at first smooth. But numerous outgrowths (primordia) typically soon appear (in an acropetal direction) which become two lobed (spikelet pair primordium), each lobe finally giving rise to a spikelet (the basic definitive structure of the grass inflorescence) with two florets (flowers). The two glumes, which arise from the pedicel of each spikelet, subtend and ensheath each spikelet and are formed in the same manner as the vegetative leaves. The glume initials emanate from the tissue of the spikelet primordium during the ontogeny of the spikelet. maizedb:pldv (ID#165572) zea_mays_anatomy staminate inflorescence ZEA:0015085 tassel (functionally male inflorescence) ZEA:0015085 The functionally-male flowering structure (staminate inflorescence) which terminates the culm (stem) of a Zea mays plant. The tassel is a branched inflorescence and consists of a central spike (rachis) and about 10-50 lateral branches. Many paired spikelets (pedicellate & sessile) arise from the central spike and lateral branches. The paired spikelets on the central spike occur in many ranks (longitudinal rows) around the central spike. The paired spikelets of the lateral branches are arranged in only two rows on the lower (adaxial) surface of each lateral branch. Each spikelet bears two male (staminate) florets, the upper and the lower floret. The development of the upper floret is about 2-3 days ahead of the lower floret (measured at anthesis). Each spikelet has a pair of leaf-like (bract-like) glumes, arising from the spikelet pedicel, which ensheath (encase) the two florets within. Within the glumes each floret is further enclosed by a pair of thin scale-like bracts - the lemma (located adjacent to the glume) and a palea (located opposite to the lemma and adjacent to the palea of the other floret in the spikelet). Within each floret, two of the three stamens are located adjacent to the margins of the palea; the third stamen is located adjacent to the midline of the lemma and is flanked by two lodicules. The two lodicules swell at the commencement of anthesis (period from floret opening to fertilization). This swelling forces apart the lemma and palea enclosing the floret, which facilitates the extrusion of the anthers via the elongation of the filaments. Following extrusion, the anthers dangle downward and shed pollen from an opening at the apex (tip) of each anther locule. The tassel exhibits an indeterminate growth pattern. Note that Zea mays is monoecious (separate male & female flowers/florets borne on the same plant). From a perspective of developmental biology the central axis and lateral branches of the tassel are at first smooth. But numerous outgrowths (primordia) typically soon appear (in an acropetal direction) which become two lobed (spikelet pair primordium), each lobe finally giving rise to a spikelet (the basic definitive structure of the grass inflorescence) with two florets (flowers). The two glumes, which arise from the pedicel of each spikelet, subtend and ensheath each spikelet and are formed in the same manner as the vegetative leaves. The glume initials emanate from the tissue of the spikelet primordium during the ontogeny of the spikelet. MaizeGDB:59445 MaizeGDB:60893 MaizeGDB:lv (ID # 165572) The spikelet is the basic unit of the grass inflorescence and each spikelet is usually subtended by a pair of leaf-like (bract-like) structures, called glumes, at its base. The two glumes are referred to as the lower glume and the upper glume. In Zea each spikelet of the tassel (staminate inflorescence) comprises two florets (flowers). Similarly each spikelet of the lateral branch (ear or pistillate inflorescence) contains initially two florets although one of these is usually arrested in its development very early on. Note that in both the staminate and pistillate inflorescences the spikelets occur in pairs (sessile & pedicellate spikelets), joined to a common pedicel. zea_mays_anatomy ZEA:0015086 spikelet ZEA:0015086 The spikelet is the basic unit of the grass inflorescence and each spikelet is usually subtended by a pair of leaf-like (bract-like) structures, called glumes, at its base. The two glumes are referred to as the lower glume and the upper glume. In Zea each spikelet of the tassel (staminate inflorescence) comprises two florets (flowers). Similarly each spikelet of the lateral branch (ear or pistillate inflorescence) contains initially two florets although one of these is usually arrested in its development very early on. Note that in both the staminate and pistillate inflorescences the spikelets occur in pairs (sessile & pedicellate spikelets), joined to a common pedicel. MaizeGDB:lv (ID # 165572) The penultimate bract-like structure that subtends the grass floret. The lemma is oriented in a position that is opposite the palea in each floret. The lemma arises from the floret pedicel immediately below the palea. See elsewhere for further information on the lemma associated with each individual floret of the male and female spikelets. Lemmas are considered to be homologous to the vegetative leaf. zea_mays_anatomy ZEA:0015087 lemma ZEA:0015087 The penultimate bract-like structure that subtends the grass floret. The lemma is oriented in a position that is opposite the palea in each floret. The lemma arises from the floret pedicel immediately below the palea. See elsewhere for further information on the lemma associated with each individual floret of the male and female spikelets. Lemmas are considered to be homologous to the vegetative leaf. MaizeGDB:lv (ID # 165572) The palea is the uppermost bract-like structure that subtends the grass floret. The palea is oriented in a position that is opposite the lemma which also subtends the floret and arises from the floret pedicel immediately below the palea. See elsewhere for further information on the palea associated with each individual floret of the male and female spikelets. The palea is a bikeeled structure and its relationship to the leaf (homology) is unknown. maizedb:pldv (ID# 165572) zea_mays_anatomy glumella ZEA:0015088 palea ZEA:0015088 The palea is the uppermost bract-like structure that subtends the grass floret. The palea is oriented in a position that is opposite the lemma which also subtends the floret and arises from the floret pedicel immediately below the palea. See elsewhere for further information on the palea associated with each individual floret of the male and female spikelets. The palea is a bikeeled structure and its relationship to the leaf (homology) is unknown. MaizeGDB:lv (ID # 165572) zea_mays_anatomy ZEA:0015089 pedicellate spikelet of ear ZEA:0015089 zea_mays_anatomy ZEA:0015090 sessile spikelet of ear ZEA:0015090 The penultimate bract-like structure that subtends the upper (pedicelled) floret of the pedicellate spikelet of the ear (pistillate inflorescence). As part of the upper floret, the inner lemma is oriented in a position that is opposite the palea & adjacent to the upper (inner) glume of the pedicellate spikelet. The lemma arises from the floret pedicel immediately below the palea. maizedb:pldv (ID# 165572) zea_mays_anatomy inner lemma of ear ZEA:0015091 lemma of upper floret of pedicellate spikelet of ear ZEA:0015091 The penultimate bract-like structure that subtends the upper (pedicelled) floret of the pedicellate spikelet of the ear (pistillate inflorescence). As part of the upper floret, the inner lemma is oriented in a position that is opposite the palea & adjacent to the upper (inner) glume of the pedicellate spikelet. The lemma arises from the floret pedicel immediately below the palea. MaizeGDB:lv (ID # 165572) The penultimate bract-like structure that subtends the lower (sessile) floret of the pedicellate spikelet of the ear (pistillate inflorescence). As part of the lower floret, the outer lemma is oriented in a position that is opposite the palea & adjacent to the lower (outer) glume of the pedicellate spikelet. The lemma arises from the floret pedicel immediately below the palea. maizedb:pldv (ID# 165572) zea_mays_anatomy outer lemma of ear ZEA:0015092 lemma of lower floret of pedicellate spikelet of ear ZEA:0015092 The penultimate bract-like structure that subtends the lower (sessile) floret of the pedicellate spikelet of the ear (pistillate inflorescence). As part of the lower floret, the outer lemma is oriented in a position that is opposite the palea & adjacent to the lower (outer) glume of the pedicellate spikelet. The lemma arises from the floret pedicel immediately below the palea. MaizeGDB:lv (ID # 165572) The penultimate bract-like structure that subtends the upper (pedicelled) floret of the sessile spikelet of the ear (pistillate inflorescence). As part of the upper floret, the inner lemma is oriented in a position that is opposite the palea & adjacent to the upper (inner) glume of the sessile spikelet. The lemma arises from the floret pedicel immediately below the palea. zea_mays_anatomy ZEA:0015093 lemma of upper floret of sessile spikelet of ear ZEA:0015093 The penultimate bract-like structure that subtends the upper (pedicelled) floret of the sessile spikelet of the ear (pistillate inflorescence). As part of the upper floret, the inner lemma is oriented in a position that is opposite the palea & adjacent to the upper (inner) glume of the sessile spikelet. The lemma arises from the floret pedicel immediately below the palea. MaizeGDB:lv (ID # 165572) The penultimate bract-like structure that subtends the lower (sessile) floret of the sessile spikelet of the ear (pistillate inflorescence). As part of the lower floret, the outer lemma is oriented in a position that is opposite the palea & adjacent to the lower (outer) glume of the sessile spikelet. The lemma arises from the floret pedicel immediately below the palea. (Vincent, ID#165572) zea_mays_anatomy ZEA:0015094 lemma of lower floret of sessile spikelet of ear ZEA:0015094 The penultimate bract-like structure that subtends the lower (sessile) floret of the sessile spikelet of the ear (pistillate inflorescence). As part of the lower floret, the outer lemma is oriented in a position that is opposite the palea & adjacent to the lower (outer) glume of the sessile spikelet. The lemma arises from the floret pedicel immediately below the palea. (Vincent, ID#165572) MaizeGDB:lv (ID # 165572) The upper (inner) of the two bract-like structures that subtend the base of the pedicelled spikelets of the ear (pistillate inflorescence). Note that each of the many paired spikelets of the ear (pistillate inflorescence) has an upper glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). (Vincent, ID#165572) zea_mays_anatomy ZEA:0015095 upper glume of pedicellate spikelet of ear ZEA:0015095 The upper (inner) of the two bract-like structures that subtend the base of the pedicelled spikelets of the ear (pistillate inflorescence). Note that each of the many paired spikelets of the ear (pistillate inflorescence) has an upper glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). (Vincent, ID#165572) MaizeGDB:lv (ID # 165572) The lower (outer) of the two bract-like structures that subtend the base of the pedicelled spikelets of the ear (pistillate inflorescence). Note that each of the many paired spikelets of the ear (pistillate inflorescence) has a lower glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). (Vincent, ID#165572) zea_mays_anatomy ZEA:0015096 lower glume of pedicellate spikelet of ear ZEA:0015096 The lower (outer) of the two bract-like structures that subtend the base of the pedicelled spikelets of the ear (pistillate inflorescence). Note that each of the many paired spikelets of the ear (pistillate inflorescence) has a lower glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). (Vincent, ID#165572) MaizeGDB:lv (ID # 165572) zea_mays_anatomy ZEA:0015097 upper floret of pedicellate spikelet of ear ZEA:0015097 zea_mays_anatomy ZEA:0015098 lower floret of pedicellate spikelet of ear ZEA:0015098 The uppermost bract-like structure that subtends the upper (pedicellate) floret of the pedicellate spikelet of the tassel (staminate inflorescence). The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. zea_mays_anatomy ZEA:0015099 palea of upper floret of pedicellate spikelet of tassel ZEA:0015099 The uppermost bract-like structure that subtends the upper (pedicellate) floret of the pedicellate spikelet of the tassel (staminate inflorescence). The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. MaizeGDB:lv (ID # 165572) The uppermost bract-like structure that subtends the lower (sessile) floret of the pedicellate spikelet of the ear (pistillate inflorescence). This palea either does not initiate or remains rudimentary. The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. (Vincent, ID#165572) zea_mays_anatomy ZEA:0015100 palea of lower floret of pedicellate spikelet of ear ZEA:0015100 The uppermost bract-like structure that subtends the lower (sessile) floret of the pedicellate spikelet of the ear (pistillate inflorescence). This palea either does not initiate or remains rudimentary. The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. (Vincent, ID#165572) MaizeGDB:lv (ID # 165572) The gynoecium development of the upper floret begins with the production of a ridge on the abaxial surface of the apical meristem of the floret, distal to the third stamen (which later degenerates). This is the stylar ridge. Continued overgrowth of the shoot apex (which becomes the ovule primordium) by the ring of stylar tissue leads to the formation of the stylar canal, which is detected as a slight protruberance on the mature ovary. (Cheng & Pareddy, ID#60893, zea_mays_anatomy ZEA:0015101 stylar ridge of upper floret of pedicellate spikelet of ear ZEA:0015101 The gynoecium development of the upper floret begins with the production of a ridge on the abaxial surface of the apical meristem of the floret, distal to the third stamen (which later degenerates). This is the stylar ridge. Continued overgrowth of the shoot apex (which becomes the ovule primordium) by the ring of stylar tissue leads to the formation of the stylar canal, which is detected as a slight protruberance on the mature ovary. (Cheng & Pareddy, ID#60893, MaizeGDB:60893 MaizeGDB:lv (ID # 165572) The gynoecium development of the lower floret begins with the production of a ridge on the abaxial surface of the apical meristem of the floret, distal to the third stamen (which later degenerates). This is the stylar ridge. While the development of this stylar ridge is very similar to that of the upper florets, the development does not proceed beyond the early ridge stage. zea_mays_anatomy ZEA:0015102 stylar ridge (abortive) of lower floret of pedicellate spikelet of ear ZEA:0015102 The gynoecium development of the lower floret begins with the production of a ridge on the abaxial surface of the apical meristem of the floret, distal to the third stamen (which later degenerates). This is the stylar ridge. While the development of this stylar ridge is very similar to that of the upper florets, the development does not proceed beyond the early ridge stage. MaizeGDB:60893 MaizeGDB:lv (ID # 165572) zea_mays_anatomy ZEA:0015103 pedicellate spikelet of tassel ZEA:0015103 zea_mays_anatomy ZEA:0015104 sessile spikelet of tassel ZEA:0015104 zea_mays_anatomy ZEA:0015105 upper floret of pedicellate spikelet of tassel ZEA:0015105 zea_mays_anatomy ZEA:0015106 lower floret of pedicellate spikelet of tassel ZEA:0015106 zea_mays_anatomy ZEA:0015107 upper floret of sessile spikelet of tassel ZEA:0015107 zea_mays_anatomy ZEA:0015108 lower floret of sessile spikelet of tassel ZEA:0015108 The upper (inner) of the two leaf-like (bract-like) structures that subtend the base of the pedicelled spikelets of the tassel (staminate inflorescence). Note that each of the many paired spikelets of the tassel (staminate inflorescence) has an upper glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). zea_mays_anatomy ZEA:0015109 upper glume of pedicellate spikelet of tassel ZEA:0015109 The upper (inner) of the two leaf-like (bract-like) structures that subtend the base of the pedicelled spikelets of the tassel (staminate inflorescence). Note that each of the many paired spikelets of the tassel (staminate inflorescence) has an upper glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). MaizeGDB:lv (ID # 165572) The lower (outer) of the two leaf-like (bract-like) structures that subtend the base of the pedicelled spikelets of the tassel (staminate inflorescence). Note that each of the many paired spikelets of the tassel (staminate inflorescence) has a lower glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). zea_mays_anatomy ZEA:0015110 lower glume of pedicellate spikelet of tassel ZEA:0015110 The lower (outer) of the two leaf-like (bract-like) structures that subtend the base of the pedicelled spikelets of the tassel (staminate inflorescence). Note that each of the many paired spikelets of the tassel (staminate inflorescence) has a lower glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). MaizeGDB:lv (ID # 165572) The upper (inner) of the two leaf-like (bract-like) structures that subtend the base of the sessile spikelets of the tassel (staminate inflorescence). Note that each of the many paired spikelets of the tassel (staminate inflorescence) has an upper glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). zea_mays_anatomy ZEA:0015111 upper glume of sessile spikelet of tassel ZEA:0015111 The upper (inner) of the two leaf-like (bract-like) structures that subtend the base of the sessile spikelets of the tassel (staminate inflorescence). Note that each of the many paired spikelets of the tassel (staminate inflorescence) has an upper glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). MaizeGDB:lv (ID # 165572) The lower (outer) of the two leaf-like (bract-like) structures that subtend the base of the sessile spikelets of the tassel (staminate inflorescence). Note that each of the many paired spikelets of the tassel (staminate inflorescence) has a lower glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). zea_mays_anatomy ZEA:0015112 lower glume of sessile spikelet of tassel ZEA:0015112 The lower (outer) of the two leaf-like (bract-like) structures that subtend the base of the sessile spikelets of the tassel (staminate inflorescence). Note that each of the many paired spikelets of the tassel (staminate inflorescence) has a lower glume. Each spikelet is subtended by a pair of glumes (lower & upper glumes). MaizeGDB:lv (ID # 165572) The uppermost bract-like structure that subtends the upper (pedicellate) floret of the pedicellate spikelet of the tassel (staminate inflorescence). The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. zea_mays_anatomy ZEA:0015113 palea of upper floret of pedicellate spikelet of tassel ZEA:0015113 The uppermost bract-like structure that subtends the upper (pedicellate) floret of the pedicellate spikelet of the tassel (staminate inflorescence). The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. MaizeGDB:lv (ID # 165572) The uppermost bract-like structure that subtends the lower (sessile) floret of the pedicellate spikelet of the tassel (staminate inflorescence). The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. zea_mays_anatomy ZEA:0015114 palea of lower floret of pedicellate spikelet of tassel ZEA:0015114 The uppermost bract-like structure that subtends the lower (sessile) floret of the pedicellate spikelet of the tassel (staminate inflorescence). The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. MaizeGDB:lv (ID # 165572) The uppermost bract-like structure that subtends the upper (pedicellate) floret of the sessile spikelet of the tassel (staminate inflorescence). The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. zea_mays_anatomy ZEA:0015115 palea of upper floret of sessile spikelet of tassel ZEA:0015115 The uppermost bract-like structure that subtends the upper (pedicellate) floret of the sessile spikelet of the tassel (staminate inflorescence). The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. MaizeGDB:lv (ID # 165572) The uppermost bract-like structure that subtends the lower (sessile) floret of the sessile spikelet of the tassel (staminate inflorescence). The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. zea_mays_anatomy ZEA:0015116 palea of lower floret of sessile spikelet of tassel ZEA:0015116 The uppermost bract-like structure that subtends the lower (sessile) floret of the sessile spikelet of the tassel (staminate inflorescence). The palea is oriented in a position that is opposite the lemma which subtends the same floret. The palea arises from the floret pedicel immediately above the lemma. MaizeGDB:lv (ID # 165572) The stamens comprise the androecium of each tassel floret (flower). Each of the three stamens comprises of a stalk-like filament which terminates in the pollen-producing anther. zea_mays_anatomy ZEA:0015117 stamens of lower floret of sessile spikelet of tassel ZEA:0015117 The stamens comprise the androecium of each tassel floret (flower). Each of the three stamens comprises of a stalk-like filament which terminates in the pollen-producing anther. MaizeGDB:lv (ID# 165572) The development of the gynoecial tissue from the floral meristem occurs during the ongoing development of the three stamen primordia.The gynoecial tissue develops via the initiation of an adaxial ridge on the remainder of the floral meristem distal to the three stamens. Soon after initiation the gynoecial tissue begins to abort and subsequently degenerates. This abortion and degeneration of this tissue in the lower floret of the pedicellate spikelet occurs before the same process occurs in the upper floret. zea_mays_anatomy ZEA:0015118 gynoecial tissue (abortive) of lower floret of pedicellate spikelet of tassel ZEA:0015118 The development of the gynoecial tissue from the floral meristem occurs during the ongoing development of the three stamen primordia.The gynoecial tissue develops via the initiation of an adaxial ridge on the remainder of the floral meristem distal to the three stamens. Soon after initiation the gynoecial tissue begins to abort and subsequently degenerates. This abortion and degeneration of this tissue in the lower floret of the pedicellate spikelet occurs before the same process occurs in the upper floret. MaizeGDB:60893 MaizeGDB:lv (ID # 165572) Two, small, scale-like. pale-green structures (glandular-like organs) found adjacent to the inner surface of the base of the lemma of the floret. The adjacent margins of the two lodicules (opposite the mid-line of the lemma) are adpressed to each other while the inner surfaces of the lodicules form an angle of approximately 80 degrees to each other. Within the triangle of basal tissue, bounded on two sides by the two lodicules, are located the three filaments of the stamens. Just prior to anthesis the lodicules grow/swell laterally and the triangle of space between the lodicules is almost obscured. The two lodicules are thought to be involved in opening of the grass floret (flower) in readiness for pollination (at anthesis they grow/become increasingly turgid and are presumed to contribute to the displacing of the adjacent lemma and glume which facilitates the exsertion of the anthers for wind pollination). Gibbs Russell et al., Grasses of southern Africa, 1990; Ambrose et al., (2000), Molecular and Genetic Analyses of the Silky1 Gene Reveal Conservation in Floral Organ Specification between Eudicots and Monocots, Molecular Cell 5:569-579. Leszek Vincent 06/2000. zea_mays_anatomy ZEA:0015119 lodicules of upper floret of pedicellate spikelet of tassel ZEA:0015119 Two, small, scale-like. pale-green structures (glandular-like organs) found adjacent to the inner surface of the base of the lemma of the floret. The adjacent margins of the two lodicules (opposite the mid-line of the lemma) are adpressed to each other while the inner surfaces of the lodicules form an angle of approximately 80 degrees to each other. Within the triangle of basal tissue, bounded on two sides by the two lodicules, are located the three filaments of the stamens. Just prior to anthesis the lodicules grow/swell laterally and the triangle of space between the lodicules is almost obscured. The two lodicules are thought to be involved in opening of the grass floret (flower) in readiness for pollination (at anthesis they grow/become increasingly turgid and are presumed to contribute to the displacing of the adjacent lemma and glume which facilitates the exsertion of the anthers for wind pollination). Gibbs Russell et al., Grasses of southern Africa, 1990; Ambrose et al., (2000), Molecular and Genetic Analyses of the Silky1 Gene Reveal Conservation in Floral Organ Specification between Eudicots and Monocots, Molecular Cell 5:569-579. Leszek Vincent 06/2000. MaizeGDB:lv (ID# 165572) Two, small, scale-like. pale-green structures (glandular-like organs) found adjacent to the inner surface of the base of the lemma of the floret. The adjacent margins of the two lodicules (opposite the mid-line of the lemma) are adpressed to each other while the inner surfaces of the lodicules form an angle of approximately 80 degrees to each other. Within the triangle of basal tissue, bounded on two sides by the two lodicules, are located the three filaments of the stamens. Just prior to anthesis the lodicules grow/swell laterally and the triangle of space between the lodicules is almost obscured. The two lodicules are thought to be involved in opening of the grass floret (flower) in readiness for pollination (at anthesis they grow/become increasingly turgid and are presumed to contribute to the displacing of the adjacent lemma and glume which facilitates the exsertion of the anthers for wind pollination). Gibbs Russell et al., Grasses of southern Africa, 1990; Ambrose et al., (2000), Molecular and Genetic Analyses of the Silky1 Gene Reveal Conservation in Floral Organ Specification between Eudicots and Monocots, Molecular Cell 5:569-579. Leszek Vincent 06/2000. zea_mays_anatomy ZEA:0015120 lodicules of lower floret of pedicellate spikelet of tassel ZEA:0015120 Two, small, scale-like. pale-green structures (glandular-like organs) found adjacent to the inner surface of the base of the lemma of the floret. The adjacent margins of the two lodicules (opposite the mid-line of the lemma) are adpressed to each other while the inner surfaces of the lodicules form an angle of approximately 80 degrees to each other. Within the triangle of basal tissue, bounded on two sides by the two lodicules, are located the three filaments of the stamens. Just prior to anthesis the lodicules grow/swell laterally and the triangle of space between the lodicules is almost obscured. The two lodicules are thought to be involved in opening of the grass floret (flower) in readiness for pollination (at anthesis they grow/become increasingly turgid and are presumed to contribute to the displacing of the adjacent lemma and glume which facilitates the exsertion of the anthers for wind pollination). Gibbs Russell et al., Grasses of southern Africa, 1990; Ambrose et al., (2000), Molecular and Genetic Analyses of the Silky1 Gene Reveal Conservation in Floral Organ Specification between Eudicots and Monocots, Molecular Cell 5:569-579. Leszek Vincent 06/2000. MaizeGDB:lv (ID# 165572) The stamens comprise the androecium of each tassel floret (flower). Each of the three stamens comprises of a stalk-like filament which terminates in the pollen-producing anther. zea_mays_anatomy ZEA:0015121 stamens of upper floret of pedicellate spikelet of tassel ZEA:0015121 The stamens comprise the androecium of each tassel floret (flower). Each of the three stamens comprises of a stalk-like filament which terminates in the pollen-producing anther. MaizeGDB:lv (ID# 165572) The stamens comprise the androecium of each tassel floret (flower). Each of the three stamens comprises of a stalk-like filament which terminates in the pollen-producing anther. zea_mays_anatomy ZEA:0015122 stamens of lower floret of pedicellate spikelet of tassel ZEA:0015122 The stamens comprise the androecium of each tassel floret (flower). Each of the three stamens comprises of a stalk-like filament which terminates in the pollen-producing anther. MaizeGDB:lv (ID# 165572) The stamens comprise the androecium of each tassel floret (flower). Each of the three stamens comprises of a stalk-like filament which terminates in the pollen-producing anther. zea_mays_anatomy ZEA:0015123 stamens of upper floret of sessile spikelet of tassel ZEA:0015123 The stamens comprise the androecium of each tassel floret (flower). Each of the three stamens comprises of a stalk-like filament which terminates in the pollen-producing anther. MaizeGDB:lv (ID#165572) zea_mays_anatomy ZEA:0015124 stamens (abortive) of upper floret of pedicellate spikelet of ear ZEA:0015124 zea_mays_anatomy ZEA:0015125 stamens (abortive) of lower floret of pedicellate spikelet of ear ZEA:0015125 zea_mays_anatomy ZEA:0015126 upper floret of sessile spikelet of ear ZEA:0015126 zea_mays_anatomy ZEA:0015127 lower floret of sessile spikelet of ear ZEA:0015127 Each spikelet in either of the inflorescences in Zea is subtended by a pair of leaf-like (bract-like) structures, called glumes, at its base. The two glumes are referred to as the lower glume and the upper glume. The spikelet is the basic unit of the grass inflorescence. In Zea each spikelet of the tassel (staminate inflorescence) comprises two florets (flowers). Similarly each spikelet of the lateral branch (ear or pistillate inflorescence) contains initially two florets although one of these is usually arrested in its development very early on. Note that in both the staminate and pistillate inflorescences the spikelets occur in pairs (sessile & pedicellate spikelets), joined to a common pedicel. zea_mays_anatomy ZEA:0015128 lower glume ZEA:0015128 Each spikelet in either of the inflorescences in Zea is subtended by a pair of leaf-like (bract-like) structures, called glumes, at its base. The two glumes are referred to as the lower glume and the upper glume. The spikelet is the basic unit of the grass inflorescence. In Zea each spikelet of the tassel (staminate inflorescence) comprises two florets (flowers). Similarly each spikelet of the lateral branch (ear or pistillate inflorescence) contains initially two florets although one of these is usually arrested in its development very early on. Note that in both the staminate and pistillate inflorescences the spikelets occur in pairs (sessile & pedicellate spikelets), joined to a common pedicel. MaizeGDB:lv (ID # 165572) Each spikelet in either of the inflorescences in Zea is subtended by a pair of leaf-like (bract-like) structures, called glumes, at its base. The two glumes are referred to as the lower glume and the upper glume. The spikelet is the basic unit of the grass inflorescence. In Zea each spikelet of the tassel (staminate inflorescence) comprises two florets (flowers). Similarly each spikelet of the lateral branch (ear or pistillate inflorescence) contains initially two florets although one of these is usually arrested in its development very early on. Note that in both the staminate and pistillate inflorescences the spikelets occur in pairs (sessile & pedicellate spikelets), joined to a common pedicel. zea_mays_anatomy ZEA:0015129 upper glume ZEA:0015129 Each spikelet in either of the inflorescences in Zea is subtended by a pair of leaf-like (bract-like) structures, called glumes, at its base. The two glumes are referred to as the lower glume and the upper glume. The spikelet is the basic unit of the grass inflorescence. In Zea each spikelet of the tassel (staminate inflorescence) comprises two florets (flowers). Similarly each spikelet of the lateral branch (ear or pistillate inflorescence) contains initially two florets although one of these is usually arrested in its development very early on. Note that in both the staminate and pistillate inflorescences the spikelets occur in pairs (sessile & pedicellate spikelets), joined to a common pedicel. MaizeGDB:lv (ID # 165572) Each spikelet in either of the inflorescences in Zea is subtended by a pair of leaf-like (bract-like) structures, called glumes, at its base. The two glumes are referred to as the lower glume and the upper glume. The spikelet is the basic unit of the grass inflorescence. In Zea each spikelet of the tassel (staminate inflorescence) comprises two florets (flowers). Similarly each spikelet of the lateral branch (ear or pistillate inflorescence) contains initially two florets although one of these is usually arrested in its development very early on. Note that in both the staminate and pistillate inflorescences the spikelets occur in pairs (sessile & pedicellate spikelets), joined to a common pedicel. Glumes are considered to be homologous to the vegetative leaf. zea_mays_anatomy ZEA:0015130 glume ZEA:0015130 Each spikelet in either of the inflorescences in Zea is subtended by a pair of leaf-like (bract-like) structures, called glumes, at its base. The two glumes are referred to as the lower glume and the upper glume. The spikelet is the basic unit of the grass inflorescence. In Zea each spikelet of the tassel (staminate inflorescence) comprises two florets (flowers). Similarly each spikelet of the lateral branch (ear or pistillate inflorescence) contains initially two florets although one of these is usually arrested in its development very early on. Note that in both the staminate and pistillate inflorescences the spikelets occur in pairs (sessile & pedicellate spikelets), joined to a common pedicel. Glumes are considered to be homologous to the vegetative leaf. MaizeGDB:Freeling & Lane (ID# 60922) MaizeGDB:lv (ID # 165572) The floret is the individual flower of the Zea mays plant. In the grass family (Poaceae, alt. Gramineae) each floret is typically bisexual (perfect), possessing both an androecium and a gynoecium. Each floret typically has a pair of bracts, the lemma and palea, which subtend the floret. It is important to note that In Zea mays the florets of the 'tassel' are functionally male (the female component (gynoecium) having aborted early on in development). The florets of the 'ear' are functionally female (the male components (androecium) having aborted early on in development). The possession of functionally male and functionally female florets (or flowers) on the same plant is a condition called monoecy. While Zea mays is functionally monoecious, the presence of both androecial and gynoecial tissue in the early stages of floret ontogeny is phylogenetically significant. Consequently, the androecium is represented in the florets of the ear and the gynoecium is represented in the florets of the tassel, even though either of these whorls is absent in the functional florets. The inclusion of both whorls in the floret ontology for the florets of ears and spikelets is based on this phylogenetically significant ontogeny. East and Hayes (1911, p. 134-135) provided the following: "Perhaps it should be mentioned in passing that the immature sex organs, so called, of maize seem endowed with the power of becoming either stamens or carpels. One often finds a normal ear ending in stamens, and nearly every plant produces lateral branches which have carpels and stamens mixed together indiscriminantly." Studies of mutants have explored these occurrences and similar occurrences in tassels, corroborating the inherent bisexual nature of the floret meristem prior to the subsequent development of the monoecious condition. zea_mays_anatomy flower ZEA:0015131 floret ZEA:0015131 The floret is the individual flower of the Zea mays plant. In the grass family (Poaceae, alt. Gramineae) each floret is typically bisexual (perfect), possessing both an androecium and a gynoecium. Each floret typically has a pair of bracts, the lemma and palea, which subtend the floret. It is important to note that In Zea mays the florets of the 'tassel' are functionally male (the female component (gynoecium) having aborted early on in development). The florets of the 'ear' are functionally female (the male components (androecium) having aborted early on in development). The possession of functionally male and functionally female florets (or flowers) on the same plant is a condition called monoecy. While Zea mays is functionally monoecious, the presence of both androecial and gynoecial tissue in the early stages of floret ontogeny is phylogenetically significant. Consequently, the androecium is represented in the florets of the ear and the gynoecium is represented in the florets of the tassel, even though either of these whorls is absent in the functional florets. The inclusion of both whorls in the floret ontology for the florets of ears and spikelets is based on this phylogenetically significant ontogeny. East and Hayes (1911, p. 134-135) provided the following: "Perhaps it should be mentioned in passing that the immature sex organs, so called, of maize seem endowed with the power of becoming either stamens or carpels. One often finds a normal ear ending in stamens, and nearly every plant produces lateral branches which have carpels and stamens mixed together indiscriminantly." Studies of mutants have explored these occurrences and similar occurrences in tassels, corroborating the inherent bisexual nature of the floret meristem prior to the subsequent development of the monoecious condition. MaizeGDB:East & Hayes (ID# 13237) MaizeGDB:lv (ID # 165572) The rachilla, or central axis, is the structure which bears the distichous glumes at the base and florets above. While the rachilla is recognizable in the spikelets of the 'tassel' in Zea mays, the rachilla of the 'ear' spikelets is much reduced. The bases of the rachillas of the ear can be considered to have anastomosed, forming the collective structure that is referred to as the cob. maizedb:pldv (ID#165572) zea_mays_anatomy central axis ZEA:0015132 rachilla ZEA:0015132 The rachilla, or central axis, is the structure which bears the distichous glumes at the base and florets above. While the rachilla is recognizable in the spikelets of the 'tassel' in Zea mays, the rachilla of the 'ear' spikelets is much reduced. The bases of the rachillas of the ear can be considered to have anastomosed, forming the collective structure that is referred to as the cob. MaizeGDB:lv (ID # 165572) The hair-like styles in maize. Each silk arises from the distal end (silk scar region) of each of the two anterior functional carpels. A vascular strand passes up through each anterior carpel into the attached silk and extends to the branched tip of the silk where it divides and extends down the length of each branch. The surface of the silk becomes covered with numerous hairs (trichomes) which arise from the epidermal cells. The hairs are most numerous along the edges of the silk. Each hair (trichome) is composed of four rows of cells, so arranged that the intercelllular spaces between the rows form a continuous opening through the center of the hair. At the base of the silk is a growth zone (intercalary growth) where new cells develop causing continuous elongation of the silk until it is pollinated and fertilization occurs. At this time the zone of elongation shrivels up, forming the place where the silk later breaks loose. The silk is perhaps best considered as consisting of a very short style without hairs, above which is the region of intercalary growth. The branched part of the silk corresponds to the stigma of other grasses. The region formed by the intercalary growth zone is an addition to the stigma and has nothing homologous to it in most grasses. maizedb:pldv (ID#165572) zea_mays_anatomy style ZEA:0015133 silk ZEA:0015133 The hair-like styles in maize. Each silk arises from the distal end (silk scar region) of each of the two anterior functional carpels. A vascular strand passes up through each anterior carpel into the attached silk and extends to the branched tip of the silk where it divides and extends down the length of each branch. The surface of the silk becomes covered with numerous hairs (trichomes) which arise from the epidermal cells. The hairs are most numerous along the edges of the silk. Each hair (trichome) is composed of four rows of cells, so arranged that the intercelllular spaces between the rows form a continuous opening through the center of the hair. At the base of the silk is a growth zone (intercalary growth) where new cells develop causing continuous elongation of the silk until it is pollinated and fertilization occurs. At this time the zone of elongation shrivels up, forming the place where the silk later breaks loose. The silk is perhaps best considered as consisting of a very short style without hairs, above which is the region of intercalary growth. The branched part of the silk corresponds to the stigma of other grasses. The region formed by the intercalary growth zone is an addition to the stigma and has nothing homologous to it in most grasses. MaizeGDB:kiesselbach (ID # 59445) MaizeGDB:lv (ID # 165572) The male reproductive organ of a flowering plant, comprising the filament (stalk-like structure) and anther (pollen producing structure). The stemens of the floret (flower) are known collectively as the androecium (M. Allaby. 1992. The Concise Oxford Dictionary of Botany, The Oxford University Press.) A Wiedemeier 5/2000; Esau, K.; Anatomy of Seed Plants 1977. Leszek Vincent 05/2000 zea_mays_anatomy ZEA:0015134 stamen ZEA:0015134 The male reproductive organ of a flowering plant, comprising the filament (stalk-like structure) and anther (pollen producing structure). The stemens of the floret (flower) are known collectively as the androecium (M. Allaby. 1992. The Concise Oxford Dictionary of Botany, The Oxford University Press.) A Wiedemeier 5/2000; Esau, K.; Anatomy of Seed Plants 1977. Leszek Vincent 05/2000 MaizeGDB:lv (ID # 165572) The pollen bearing part of the stamen. In flowering plants, the tip of the stamen, which contains the pollen sacs and in which the pollen grains are formed; usually elevated by means of a filament. zea_mays_anatomy ZEA:0015135 anther ZEA:0015135 The pollen bearing part of the stamen. In flowering plants, the tip of the stamen, which contains the pollen sacs and in which the pollen grains are formed; usually elevated by means of a filament. MaizeGDB:esau (ID # 139825) MaizeGDB:lv (ID # 165572) - http //www.harcourt.com/dictionary/def/6/2/2/0/622000.html The stalk-like structure of the stamen, which bears the anther. (M.Allaby. 1992. The Concise Oxford Dictionary of Botany, The Oxford University Press.). zea_mays_anatomy ZEA:0015136 filament ZEA:0015136 The stalk-like structure of the stamen, which bears the anther. (M.Allaby. 1992. The Concise Oxford Dictionary of Botany, The Oxford University Press.). MaizeGDB:lv (ID # 165572) A small rounded or scale-like structure (glandular-like organ) found between the base of the stamens in the grass floret (flower). The lodicules (usually 2) each arise adjacent to the base of the ovary and are between the stamens adjacent to the lemma of the grass floret. Note that the anterior lodicule (the third lodicule), adjacent to the palea, is suppressed in most grass species. This suppression results in the trimerous arrangement of the lodicules together with the stamens and carpels being overlooked. The lodicules are thought to be involved in opening of the grass flower in readiness for pollination (they become turgid at anthesis, thus opening (pushing apart) the lemma and palea and facilitating wind pollination). maizedb:pldv (ID#165572 zea_mays_anatomy glumella ZEA:0015137 lodicule ZEA:0015137 A small rounded or scale-like structure (glandular-like organ) found between the base of the stamens in the grass floret (flower). The lodicules (usually 2) each arise adjacent to the base of the ovary and are between the stamens adjacent to the lemma of the grass floret. Note that the anterior lodicule (the third lodicule), adjacent to the palea, is suppressed in most grass species. This suppression results in the trimerous arrangement of the lodicules together with the stamens and carpels being overlooked. The lodicules are thought to be involved in opening of the grass flower in readiness for pollination (they become turgid at anthesis, thus opening (pushing apart) the lemma and palea and facilitating wind pollination). :Ambrose et al. , (2000). Molecular and Genetic Analysis of the Silky1 Gene Reveal Conservation in Floral Organ Specification between Eudicots and Monocots , Molecular Cell 5 569-579 :Gibbs Russel et al. , (1990). Grasses of southern Africa MaizeGDB:lv (ID # 165572) The androecium is the male reproductive whorl of a flowering plant, comprising the stamen(s). Each stamen of the androecium usually comprises of a filament (stalk-like structure) and anther (pollen producing structure). In some taxa one or more of the stamens may be sterile (producing no pollen). These modified stamens are called staminodes. zea_mays_anatomy ZEA:0015138 androecium ZEA:0015138 The androecium is the male reproductive whorl of a flowering plant, comprising the stamen(s). Each stamen of the androecium usually comprises of a filament (stalk-like structure) and anther (pollen producing structure). In some taxa one or more of the stamens may be sterile (producing no pollen). These modified stamens are called staminodes. Allaby 1992:The Concise Oxford Dictionary of Botany Esau 1977:Anatomy of Seed Plants MaizeGDB:275295 MaizeGDB:lv (ID # 165572) MaizeGDB:wiedemeier (ID # 292238) Gynoecium is the collective term for all of the carpels or pistils of a flower (floret). Each carpel or pistil comprises of a stigma, style and ovary. In Zea the silk comprises the stigma and extended style. maizedb:pldv (ID# 165572) zea_mays_anatomy pistil ZEA:0015139 gynoecium ZEA:0015139 Gynoecium is the collective term for all of the carpels or pistils of a flower (floret). Each carpel or pistil comprises of a stigma, style and ovary. In Zea the silk comprises the stigma and extended style. MaizeGDB:lv (ID # 165572) The husk structure consists mostly of the husk sheath. The husk sheath is the proximal (basal) portion of the husk that initiates at each of the nodes of the lateral branch (shank). The husk sheathes are much broader and thinner than the sheathes of adult and juvenile leaves. The broadness of the husk sheathes enable them to cover much of the circumference of the developing ear. The distal end of the husk sheath ends with the husk ligule region which is terminated with a diminutive (short) or extended husk leaf (flag leaf). The outer husks (lowermost/most proximal) on the lateral branch (shank) are distichous (in two vertical ranks or rows on opposite sides of an axis) like the adult & juvenile leaves. While the inner (upper) husks are polystichous (arranged in several rows). Note that the term husk (instead of husk sheath) is colloquially used for the modified leaf tissue which surrounds the ear and the term is seldom associated with husk ligule and husk leaf (flag leaf). However, botanically, the term husk should be used for the entire structure (fide Kiesselbach, 1949), comprising the husk sheath, husk ligule and husk leaf (the latter components frequently being very diminutive). The perspective that husks are somewhat homologous with the adult and juvenile leaves justifies the usage of the term husk sheath for the predominant portion of the husk which surrounds the ear. maizedb:pldv (ID # 165572) zea_mays_anatomy husk ZEA:0015140 husk sheath ZEA:0015140 The husk structure consists mostly of the husk sheath. The husk sheath is the proximal (basal) portion of the husk that initiates at each of the nodes of the lateral branch (shank). The husk sheathes are much broader and thinner than the sheathes of adult and juvenile leaves. The broadness of the husk sheathes enable them to cover much of the circumference of the developing ear. The distal end of the husk sheath ends with the husk ligule region which is terminated with a diminutive (short) or extended husk leaf (flag leaf). The outer husks (lowermost/most proximal) on the lateral branch (shank) are distichous (in two vertical ranks or rows on opposite sides of an axis) like the adult & juvenile leaves. While the inner (upper) husks are polystichous (arranged in several rows). Note that the term husk (instead of husk sheath) is colloquially used for the modified leaf tissue which surrounds the ear and the term is seldom associated with husk ligule and husk leaf (flag leaf). However, botanically, the term husk should be used for the entire structure (fide Kiesselbach, 1949), comprising the husk sheath, husk ligule and husk leaf (the latter components frequently being very diminutive). The perspective that husks are somewhat homologous with the adult and juvenile leaves justifies the usage of the term husk sheath for the predominant portion of the husk which surrounds the ear. MaizeGDB:kiesselbach (ID# 59445) MaizeGDB:lv (ID# 165572) The husk leaf (lamina) is a small (short, reduced - less than 20 mm) portion of modified leaf-blade tissue that is present at the distal end of each husk. The husk leaf region commences with a modified and diminutive ligular region and extends into a tapered lamina which is photosynthetic. The husk leaf is considered to be somewhat homologous with the leaf blade (lamina) of the adult and juvenile leaves. In all occurrences the husk leaf (lamina) lacks the well developed central midrib (midvein) and the widespread lateral veins are much less robust.The husk leaf is reduced in most forms of dent corn. However, in sweet corns the husk leaves are considerably longer (60 mm or longer) and are frequently referred to as flag leaves. These 'flag leaves' should not be confused with the "flag leaf" (ZEA:15148). Where the husk leaves are well developed (flag leaves) the husk leaves are noticeably lacking in rigidity. maizedb:ID# 77179 maizedb:http://www.agron.missouri.edu/mnl/60/94bird.html maizedb:http://www.agron.missouri.edu/mnl/77/08has.html zea_mays_anatomy flag leaves ZEA:0015141 husk leaf ZEA:0015141 The husk leaf (lamina) is a small (short, reduced - less than 20 mm) portion of modified leaf-blade tissue that is present at the distal end of each husk. The husk leaf region commences with a modified and diminutive ligular region and extends into a tapered lamina which is photosynthetic. The husk leaf is considered to be somewhat homologous with the leaf blade (lamina) of the adult and juvenile leaves. In all occurrences the husk leaf (lamina) lacks the well developed central midrib (midvein) and the widespread lateral veins are much less robust.The husk leaf is reduced in most forms of dent corn. However, in sweet corns the husk leaves are considerably longer (60 mm or longer) and are frequently referred to as flag leaves. These 'flag leaves' should not be confused with the "flag leaf" (ZEA:15148). Where the husk leaves are well developed (flag leaves) the husk leaves are noticeably lacking in rigidity. MaizeGDB:ID# 106158 MaizeGDB:kiesselbach (ID# 59445) MaizeGDB:lv (ID# 165572) The husk ligule in Zea mays is sometimes absent. When present it takes the form of a diminutive protruding line of tissue on the inner/upper (adaxial) surface of the husk leaf at the boundary between the husk sheath and the tapered husk leaf (lamina). As in the ligules of adult and juvenile leaves, this unique line of epidermal tissue appears to be composed of 'fused hairs'. The husk leaf ligule is relatively short (laterally), spanning the width of the tapered end of the distal end of the husk. zea_mays_anatomy ZEA:0015142 husk ligule ZEA:0015142 The husk ligule in Zea mays is sometimes absent. When present it takes the form of a diminutive protruding line of tissue on the inner/upper (adaxial) surface of the husk leaf at the boundary between the husk sheath and the tapered husk leaf (lamina). As in the ligules of adult and juvenile leaves, this unique line of epidermal tissue appears to be composed of 'fused hairs'. The husk leaf ligule is relatively short (laterally), spanning the width of the tapered end of the distal end of the husk. MaizeGDB:lv (ID# 165572) The development of the gynoecial tissue from the floral meristem occurs during the ongoing development of the three stamen primordia.The gynoecial tissue develops via the initiation of an adaxial ridge on the remainder of the floral meristem distal to the three stamens. Soon after initiation the gynoecial tissue begins to abort and subsequently degenerates. This abortion and degeneration of this tissue in the lower floret of the sessile spikelet occurs before the same process occurs in the upper floret. zea_mays_anatomy ZEA:0015143 gynoecial tissue (abortive) of lower floret of sessile spikelet of tassel ZEA:0015143 The development of the gynoecial tissue from the floral meristem occurs during the ongoing development of the three stamen primordia.The gynoecial tissue develops via the initiation of an adaxial ridge on the remainder of the floral meristem distal to the three stamens. Soon after initiation the gynoecial tissue begins to abort and subsequently degenerates. This abortion and degeneration of this tissue in the lower floret of the sessile spikelet occurs before the same process occurs in the upper floret. MaizeGDB:60893 MaizeGDB:lv (ID# 165572) Two, small, scale-like. pale-green structures (glandular-like organs) found adjacent to the inner surface of the base of the lemma of the floret. The adjacent margins of the two lodicules (opposite the mid-line of the lemma) are adpressed to each other while the inner surfaces of the lodicules form an angle of approximately 80 degrees to each other. Within the triangle of basal tissue, bounded on two sides by the two lodicules, are located the three filaments of the stamens. Just prior to anthesis the lodicules grow/swell laterally and the triangle of space between the lodicules is almost obscured. The two lodicules are thought to be involved in opening of the grass floret (flower) in readiness for pollination (at anthesis they grow/become increasingly turgid and are presumed to contribute to the displacing of the adjacent lemma and glume which facilitates the exsertion of the anthers for wind pollination). Gibbs Russell et al., Grasses of southern Africa, 1990; Ambrose et al., (2000), Molecular and Genetic Analyses of the Silky1 Gene Reveal Conservation in Floral Organ Specification between Eudicots and Monocots, Molecular Cell 5:569-579. Leszek Vincent 06/2000. zea_mays_anatomy ZEA:0015144 lodicules of lower floret of sessile spikelet of tassel ZEA:0015144 Two, small, scale-like. pale-green structures (glandular-like organs) found adjacent to the inner surface of the base of the lemma of the floret. The adjacent margins of the two lodicules (opposite the mid-line of the lemma) are adpressed to each other while the inner surfaces of the lodicules form an angle of approximately 80 degrees to each other. Within the triangle of basal tissue, bounded on two sides by the two lodicules, are located the three filaments of the stamens. Just prior to anthesis the lodicules grow/swell laterally and the triangle of space between the lodicules is almost obscured. The two lodicules are thought to be involved in opening of the grass floret (flower) in readiness for pollination (at anthesis they grow/become increasingly turgid and are presumed to contribute to the displacing of the adjacent lemma and glume which facilitates the exsertion of the anthers for wind pollination). Gibbs Russell et al., Grasses of southern Africa, 1990; Ambrose et al., (2000), Molecular and Genetic Analyses of the Silky1 Gene Reveal Conservation in Floral Organ Specification between Eudicots and Monocots, Molecular Cell 5:569-579. Leszek Vincent 06/2000. MaizeGDB:lv (ID# 165572) Two, small, scale-like. pale-green structures (glandular-like organs) found adjacent to the inner surface of the base of the lemma of the floret. The adjacent margins of the two lodicules (opposite the mid-line of the lemma) are adpressed to each other while the inner surfaces of the lodicules form an angle of approximately 80 degrees to each other. Within the triangle of basal tissue, bounded on two sides by the two lodicules, are located the three filaments of the stamens. Just prior to anthesis the lodicules grow/swell laterally and the triangle of space between the lodicules is almost obscured. The two lodicules are thought to be involved in opening of the grass floret (flower) in readiness for pollination (at anthesis they grow/become increasingly turgid and are presumed to contribute to the displacing of the adjacent lemma and glume which facilitates the exsertion of the anthers for wind pollination). Gibbs Russell et al., Grasses of southern Africa, 1990; Ambrose et al., (2000), Molecular and Genetic Analyses of the Silky1 Gene Reveal Conservation in Floral Organ Specification between Eudicots and Monocots, Molecular Cell 5:569-579. Leszek Vincent 06/2000. zea_mays_anatomy ZEA:0015145 lodicules of upper floret of sessile spikelet of tassel ZEA:0015145 Two, small, scale-like. pale-green structures (glandular-like organs) found adjacent to the inner surface of the base of the lemma of the floret. The adjacent margins of the two lodicules (opposite the mid-line of the lemma) are adpressed to each other while the inner surfaces of the lodicules form an angle of approximately 80 degrees to each other. Within the triangle of basal tissue, bounded on two sides by the two lodicules, are located the three filaments of the stamens. Just prior to anthesis the lodicules grow/swell laterally and the triangle of space between the lodicules is almost obscured. The two lodicules are thought to be involved in opening of the grass floret (flower) in readiness for pollination (at anthesis they grow/become increasingly turgid and are presumed to contribute to the displacing of the adjacent lemma and glume which facilitates the exsertion of the anthers for wind pollination). Gibbs Russell et al., Grasses of southern Africa, 1990; Ambrose et al., (2000), Molecular and Genetic Analyses of the Silky1 Gene Reveal Conservation in Floral Organ Specification between Eudicots and Monocots, Molecular Cell 5:569-579. Leszek Vincent 06/2000. MaizeGDB:lv (ID# 165572) The development of the gynoecial tissue from the floral meristem occurs during the ongoing development of the three stamen primordia.The gynoecial tissue develops via the initiation of an adaxial ridge on the remainder of the floral meristem distal to the three stamens. Soon after initiation the gynoecial tissue begins to abort and subsequently degenerates. This abortion and degeneration of this tissue in the upper floret of the sessile spikelet occurs after the same process occurs in the lower floret. zea_mays_anatomy ZEA:0015146 gynoecial tissue (abortive) of upper floret of sessile spikelet of tassel ZEA:0015146 The development of the gynoecial tissue from the floral meristem occurs during the ongoing development of the three stamen primordia.The gynoecial tissue develops via the initiation of an adaxial ridge on the remainder of the floral meristem distal to the three stamens. Soon after initiation the gynoecial tissue begins to abort and subsequently degenerates. This abortion and degeneration of this tissue in the upper floret of the sessile spikelet occurs after the same process occurs in the lower floret. MaizeGDB:60893 MaizeGDB:lv (ID# 165572) The development of the gynoecial tissue from the floral meristem occurs during the ongoing development of the three stamen primordia.The gynoecial tissue develops via the initiation of an adaxial ridge on the remainder of the floral meristem distal to the three stamens. Soon after initiation the gynoecial tissue begins to abort and subsequently degenerates. This abortion and degeneration of this tissue in the upper floret of the pedicellate spikelet occurs after the same process occurs in the lower floret. zea_mays_anatomy ZEA:0015147 gynoecial tissue (abortive) of upper floret of pedicellate spikelet of tassel ZEA:0015147 The development of the gynoecial tissue from the floral meristem occurs during the ongoing development of the three stamen primordia.The gynoecial tissue develops via the initiation of an adaxial ridge on the remainder of the floral meristem distal to the three stamens. Soon after initiation the gynoecial tissue begins to abort and subsequently degenerates. This abortion and degeneration of this tissue in the upper floret of the pedicellate spikelet occurs after the same process occurs in the lower floret. MaizeGDB:lv (ID# 165572) The last leaf to emerge in a determinate plant in the Poaceae (determinate growth: formation of a restricted number of lateral organs by an apical meristem; apical meristem terminates growth e.g. tassel & lateral branch meristems). Referred to as the "flag leaf" in cereal (grain) crops. The term 'flag leaf' should not be confused with 'flag leaves' which is a synonym term frequently used for the husk leaf (extended lamina) of the husks of sweet corn varieties. The flag leaf is frequently much less robust than the other adult leaves. In some cases the midrib is much reduced rendering the leaf very mobile. http://www.agriknowledge.co.uk/Dessac/Definitions/finallf.html:; synonym:final leaf zea_mays_anatomy ZEA:0015148 flag leaf ZEA:0015148 The last leaf to emerge in a determinate plant in the Poaceae (determinate growth: formation of a restricted number of lateral organs by an apical meristem; apical meristem terminates growth e.g. tassel & lateral branch meristems). Referred to as the "flag leaf" in cereal (grain) crops. The term 'flag leaf' should not be confused with 'flag leaves' which is a synonym term frequently used for the husk leaf (extended lamina) of the husks of sweet corn varieties. The flag leaf is frequently much less robust than the other adult leaves. In some cases the midrib is much reduced rendering the leaf very mobile. MaizeGDB:esau (ID# 139825) MaizeGDB:lv (ID # 165572) The terms and definitions of the various tissues in Zea mays. zea_mays_anatomy ZEA:0015149 tissue ZEA:0015149 The terms and definitions of the various tissues in Zea mays. MaizeGDB:lv (ID# 165572) A group of meristematic cells at the apex of the root that by cell division (mitosis) produce the precursors of the primary tissues of the root. zea_mays_anatomy ZEA:0015150 root apical meristem ZEA:0015150 A group of meristematic cells at the apex of the root that by cell division (mitosis) produce the precursors of the primary tissues of the root. MaizeGDB:Esau (ID# 139825) MaizeGDB:lv (ID# 165572) A group of meristematic cells at the apex of the shoot that by cell division (mitosis) produce the precursors of the primary tissues of the shoot; may be vegetative, initiating vegetative tissues and organs, or reproductive, initiating reproductive tissues and organs. zea_mays_anatomy ZEA:0015151 shoot apical meristem ZEA:0015151 A group of meristematic cells at the apex of the shoot that by cell division (mitosis) produce the precursors of the primary tissues of the shoot; may be vegetative, initiating vegetative tissues and organs, or reproductive, initiating reproductive tissues and organs. MaizeGDB:Esau (ID# 139825) MaizeGDB:lv (ID# 165572) zea_mays_anatomy ZEA:0015152 vegetative meristem ZEA:0015152 zea_mays_anatomy ZEA:0015153 spikelet pair meristem ZEA:0015153 The floret meristem is derived/develops from the spikelet meristem. The floret meristem produces the floret (lemma, palea, androecium & gynoecium). Normally two florets are derived from one spikelet meristem. zea_mays_anatomy ZEA:0015154 floret meristem ZEA:0015154 The floret meristem is derived/develops from the spikelet meristem. The floret meristem produces the floret (lemma, palea, androecium & gynoecium). Normally two florets are derived from one spikelet meristem. MaizeGDB:lv (ID# 165572) The meristem which produces the tassel and the ear inflorescences. The tassel (functionally male inflorescence) meristem is derived from the apical meristem of the growing point of the determinate culm. An ear meristem is derived from the apical meristem of a lateral branch which produces the ear (functionally female inflorescence). zea_mays_anatomy ZEA:0015155 inflorescence meristem ZEA:0015155 The meristem which produces the tassel and the ear inflorescences. The tassel (functionally male inflorescence) meristem is derived from the apical meristem of the growing point of the determinate culm. An ear meristem is derived from the apical meristem of a lateral branch which produces the ear (functionally female inflorescence). MaizeGDB:lv (ID# 165572) zea_mays_anatomy ZEA:0015156 tassel meristem ZEA:0015156 The ear meristem gives rise to numerous spikelet-pair primordia which are arranged in characteristic rows along the longitudinal axis of the ear (functionally female inflorescence). Each spikelet-pair primordium exhibits determinate growth and differentiates into a pedicellate and sessile spikelet (each of these spikelets produces an upper and lower floret). zea_mays_anatomy ZEA:0015157 ear meristem ZEA:0015157 The ear meristem gives rise to numerous spikelet-pair primordia which are arranged in characteristic rows along the longitudinal axis of the ear (functionally female inflorescence). Each spikelet-pair primordium exhibits determinate growth and differentiates into a pedicellate and sessile spikelet (each of these spikelets produces an upper and lower floret). MaizeGDB:lv (ID# 165572) The meristem which gives rise to a lateral root (ZEA:15065). These (adventitious) lateral roots emerge from the primary root (radicle, tap root) at varying points behind the zone of root hair formation. They originate from the pericycle. zea_mays_anatomy ZEA:0015158 lateral root meristem ZEA:0015158 The meristem which gives rise to a lateral root (ZEA:15065). These (adventitious) lateral roots emerge from the primary root (radicle, tap root) at varying points behind the zone of root hair formation. They originate from the pericycle. MaizeGDB:lv (ID# 165572) The meristem located in the axil of a leaf and giving rise to an axilllary bud. The axillary meristem is initiated in association with the formation of a leaf primordium. zea_mays_anatomy ZEA:0015159 axillary meristem ZEA:0015159 The meristem located in the axil of a leaf and giving rise to an axilllary bud. The axillary meristem is initiated in association with the formation of a leaf primordium. MaizeGDB:Esau (ID# 139825) MaizeGDB:ID# 402668 MaizeGDB:lv (ID# 165572) Shoot meristematic tissue arising other than at the apex or in association with a leaf primordium. This is the same meristem which gives rise to shoots, collectively called tillers. Observations indicate that while axillary buds may be involved in adventitious shoot growth (formation of tillers), several of these shoots (tillers) can arise from a single node. These observations suggest that the adventitious shoot meristem is recognizably distinct from the axillary bud meristem. zea_mays_anatomy ZEA:0015160 adventitious shoot meristem ZEA:0015160 Shoot meristematic tissue arising other than at the apex or in association with a leaf primordium. This is the same meristem which gives rise to shoots, collectively called tillers. Observations indicate that while axillary buds may be involved in adventitious shoot growth (formation of tillers), several of these shoots (tillers) can arise from a single node. These observations suggest that the adventitious shoot meristem is recognizably distinct from the axillary bud meristem. MaizeGDB:lv (ID# 165572) A meristematic tissue consisting of parallel layers of cells dividing anticlinally (perpendicular to the leaf surface). The divisions in this meristem constitute a major part of the intercalary growth by which the leaf reaches its mature size (with respect to surface area; periclinal divisions are responsible for increasing leaf thickness). (Esau, ID#139825; Vincent ID#165572, 2002) zea_mays_anatomy ZEA:0015161 plate meristem ZEA:0015161 A meristematic tissue consisting of parallel layers of cells dividing anticlinally (perpendicular to the leaf surface). The divisions in this meristem constitute a major part of the intercalary growth by which the leaf reaches its mature size (with respect to surface area; periclinal divisions are responsible for increasing leaf thickness). (Esau, ID#139825; Vincent ID#165572, 2002) MaizeGDB:Esau (ID# 139825) MaizeGDB:lv (ID# 165572) The meristem which gives rise to the primary root (ZEA:15061). The primary root (radicle or tap root) is the initial root structure which emerges from the embryo of the caryopsis (kernel/seed). The primary root is formed early during embryogenesis, becoming defined as a distinctive region 10-15 days after pollination. zea_mays_anatomy ZEA:0015162 primary root meristem ZEA:0015162 The meristem which gives rise to the primary root (ZEA:15061). The primary root (radicle or tap root) is the initial root structure which emerges from the embryo of the caryopsis (kernel/seed). The primary root is formed early during embryogenesis, becoming defined as a distinctive region 10-15 days after pollination. MaizeGDB:lv (ID# 165572) zea_mays_anatomy ZEA:0015163 seminal root meristem ZEA:0015163 The meristem which gives rise to the crown roots (ZEA:15066).There are two spatial components of the adventitious root system. 1. A subterranean (below-ground) origin; 2. An aerial (above-ground) origin. The subterranean adventitious roots are frequently called crown roots because they originate from the basal portion of the growing stem known as the crown. The first crown roots (4-5), arranged in a whorl, appear at the base of the second internode about as soon as the tip of the coleoptile reaches the soil surface. A few of the subsequent higher internodes may have a similar number of crown roots (in whorls), after which the successive internodes have more and larger crown roots up to 2-3 internodes above the soil surface. zea_mays_anatomy ZEA:0015164 crown root meristem ZEA:0015164 The meristem which gives rise to the crown roots (ZEA:15066).There are two spatial components of the adventitious root system. 1. A subterranean (below-ground) origin; 2. An aerial (above-ground) origin. The subterranean adventitious roots are frequently called crown roots because they originate from the basal portion of the growing stem known as the crown. The first crown roots (4-5), arranged in a whorl, appear at the base of the second internode about as soon as the tip of the coleoptile reaches the soil surface. A few of the subsequent higher internodes may have a similar number of crown roots (in whorls), after which the successive internodes have more and larger crown roots up to 2-3 internodes above the soil surface. MaizeGDB:lv (ID# 165572) The meristem which gives rise to the prop roots (ZEA:15068). Prop ('brace') roots are crown roots which have an aerial (above-ground) origin. They emerge from the extreme basal portion of 2-3 internodes above the soil surface. zea_mays_anatomy ZEA:0015165 prop root meristem ZEA:0015165 The meristem which gives rise to the prop roots (ZEA:15068). Prop ('brace') roots are crown roots which have an aerial (above-ground) origin. They emerge from the extreme basal portion of 2-3 internodes above the soil surface. MaizeGDB:lv (ID# 165572) The meristem which gives rise to the subterranean crown roots (ZEA:15067).The subterranean crown roots are a component of the adventitious root system. They are termed crown roots because they originate from the basal portion of the growing stem known as the crown. The first subterranean crown roots (4-5), arranged in a whorl, appear at the base of the second internode about as soon as the tip of the coleoptile reaches the soil surface. A few of the subsequent higher internodes may have a similar number of crown roots (in whorls), after which the successive internodes have more and larger crown roots up to 2-3 internodes above the soil surface. zea_mays_anatomy ZEA:0015166 subterranean crown root meristem ZEA:0015166 The meristem which gives rise to the subterranean crown roots (ZEA:15067).The subterranean crown roots are a component of the adventitious root system. They are termed crown roots because they originate from the basal portion of the growing stem known as the crown. The first subterranean crown roots (4-5), arranged in a whorl, appear at the base of the second internode about as soon as the tip of the coleoptile reaches the soil surface. A few of the subsequent higher internodes may have a similar number of crown roots (in whorls), after which the successive internodes have more and larger crown roots up to 2-3 internodes above the soil surface. MaizeGDB:lv (ID# 165572) The meristem which gives rise to the seminal lateral roots (ZEA:15064). Some of the lateral roots of the maize plant comprise the seminal root system. These lateral roots are present in the ungerminated caryopsis (kernel, seed) - they are formed during embryogenesis. The seminal lateral roots arise from 3 to 7 seminal root primordia. zea_mays_anatomy ZEA:0015167 seminal lateral root meristem ZEA:0015167 The meristem which gives rise to the seminal lateral roots (ZEA:15064). Some of the lateral roots of the maize plant comprise the seminal root system. These lateral roots are present in the ungerminated caryopsis (kernel, seed) - they are formed during embryogenesis. The seminal lateral roots arise from 3 to 7 seminal root primordia. MaizeGDB:lv (ID# 165572) The meristem which gives rise to the adventitious root system. The adventitious root system consists of all those roots that arise in the basal intercalary meristem of the lower internodes (above the first internode) of the culm (stem). The adventitious root system comprises the bulk of the lateral roots of the maize plant. zea_mays_anatomy ZEA:0015168 adventitious root meristem ZEA:0015168 The meristem which gives rise to the adventitious root system. The adventitious root system consists of all those roots that arise in the basal intercalary meristem of the lower internodes (above the first internode) of the culm (stem). The adventitious root system comprises the bulk of the lateral roots of the maize plant. MaizeGDB:lv (ID# 165572) The meristem which gives rise to a root branch (ZEA:15069). A root branch is an adventitious root that emerges from any of the various types of lateral root. Root branches arise at varying points behind (posterior to) the zone of root hair formation on the primary root. Root branches emerge from the surface of the main roots (the various types of lateral roots) at irregular intervals. When a root branches, the initial of each branch is formed from cells of the pericycle. Via cell division a bulging hemispherical mass of meristematic tissue is formed. The outer part of this forms the beginning of the rootcap, while the cells of the growing point are near the flat basal part of the hemispherical mass. zea_mays_anatomy ZEA:0015169 root branch meristem ZEA:0015169 The meristem which gives rise to a root branch (ZEA:15069). A root branch is an adventitious root that emerges from any of the various types of lateral root. Root branches arise at varying points behind (posterior to) the zone of root hair formation on the primary root. Root branches emerge from the surface of the main roots (the various types of lateral roots) at irregular intervals. When a root branches, the initial of each branch is formed from cells of the pericycle. Via cell division a bulging hemispherical mass of meristematic tissue is formed. The outer part of this forms the beginning of the rootcap, while the cells of the growing point are near the flat basal part of the hemispherical mass. MaizeGDB:lv (ID# 165572) A dry, one-seeded, indehiscent fruit with the seed coat fused to the pericarp. The caryopsis includes the ovary. The caryopsis is the typical fruit structure of the grass (Poaceae / Gramineae) family. maizedb:ID # 11089 zea_mays_anatomy grain kernel seed ZEA:0015170 caryopsis ZEA:0015170 A dry, one-seeded, indehiscent fruit with the seed coat fused to the pericarp. The caryopsis includes the ovary. The caryopsis is the typical fruit structure of the grass (Poaceae / Gramineae) family. Chapman:The Biology of Grasses - ISBN 0 85199 111 4 Harris & Harris:Plant Identification Terminology - An Illustrated Glossary , ISBN 0 9640221 5 X MaizeGDB:lv (ID# 165572) The term tiller is a collective term used for all of the various forms of adventitious shoot which is produced by Zea mays. Tillers are produced by adventitous shoot meristematic tissue (ZEA:xxx). Observations indicate that while axillary buds may be involved in adventitious shoot growth (formation of tillers), several of these shoots (tillers) can arise from a single node. maizedb:ID# 402669 maizedb:pldv (ID# 165572) zea_mays_anatomy adventitious shoot ZEA:0015171 tiller ZEA:0015171 The term tiller is a collective term used for all of the various forms of adventitious shoot which is produced by Zea mays. Tillers are produced by adventitous shoot meristematic tissue (ZEA:xxx). Observations indicate that while axillary buds may be involved in adventitious shoot growth (formation of tillers), several of these shoots (tillers) can arise from a single node. MaizeGDB:lv (ID# 165572) A leaf primordium is typically referred to as a cell/an organized series of cells in their earliest stage of differentiation with the ontogenetic goal of forming a leaf. A leaf primordium is initiated by cell divisions in the peripheral region of the shoot apex, more or less far below the distal zone of the apical meristem. The first divisions occur in one or more layers beneath the protoderm and are periclinal to the surface of the shoot apex. In Zea the leaf primordium originates from about 250 cells in at least two layers forming a ring of founder cells within the apical meristem tissue associated with the leaf. Each founder cell divides about the same number of times to form the 6 mm square-shaped leaf primordium. The primordial stages of development ends when the lateral veins are complete and the periclinal divisions of the ligule are in progress. Three stages of leaf development are noted: founder cell (meristem founder cell), primordial and postprimordial. The location of each primordium, in relation to the sites of the previously formed leaves, is determined by the phyllotaxy. zea_mays_anatomy ZEA:0015172 leaf primordium ZEA:0015172 A leaf primordium is typically referred to as a cell/an organized series of cells in their earliest stage of differentiation with the ontogenetic goal of forming a leaf. A leaf primordium is initiated by cell divisions in the peripheral region of the shoot apex, more or less far below the distal zone of the apical meristem. The first divisions occur in one or more layers beneath the protoderm and are periclinal to the surface of the shoot apex. In Zea the leaf primordium originates from about 250 cells in at least two layers forming a ring of founder cells within the apical meristem tissue associated with the leaf. Each founder cell divides about the same number of times to form the 6 mm square-shaped leaf primordium. The primordial stages of development ends when the lateral veins are complete and the periclinal divisions of the ligule are in progress. Three stages of leaf development are noted: founder cell (meristem founder cell), primordial and postprimordial. The location of each primordium, in relation to the sites of the previously formed leaves, is determined by the phyllotaxy. MaizeGDB:Esau (ID# 139825) MaizeGDB:Freeling & Lane (ID# 60922) MaizeGDB:lv (ID# 165572) A group of meristematic cells at the apex of root or shoot that by cell division produce the precursors of the primary tissues of root or shoot. The apical meristem may be vegetative, initiating vegetative tissues and organs, or reproductive, initiating reproductive tissues and organs. zea_mays_anatomy ZEA:0015173 apical meristem ZEA:0015173 A group of meristematic cells at the apex of root or shoot that by cell division produce the precursors of the primary tissues of root or shoot. The apical meristem may be vegetative, initiating vegetative tissues and organs, or reproductive, initiating reproductive tissues and organs. MaizeGDB:Esau (ID# 139825 A group of about 250 cells arranged in at least two layers forming a ring within the shoot apical meristem. zea_mays_anatomy ZEA:0015174 founder cells ZEA:0015174 A group of about 250 cells arranged in at least two layers forming a ring within the shoot apical meristem. MaizeGDB:Freeling & Lane (ID# 60922) MaizeGDB:lv (ID# 165572) zea_mays_anatomy ZEA:0015175 leaf postprimordium ZEA:0015175 zea_mays_anatomy ZEA:0015176 gametophyte ZEA:0015176 zea_mays_anatomy ZEA:0015177 sporophyte ZEA:0015177 zea_mays_anatomy ZEA:0015178 seed ZEA:0015178 zea_mays_anatomy ZEA:0015179 embryo ZEA:0015179 zea_mays_anatomy ZEA:0015180 shoot ZEA:0015180 DAG-Edit 1.419 rev 3 09:08:2005 16:02 zea_mays_anatomy 1.0 gwg autogenerated-by: DAG-Edit version 1.410 date: Thu Feb 12 16:13:57 CST 2004 saved-by: Leszek version: $Revision: 1.1 $