isthmus |
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STRUCTURE |
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A narrower portion connecting two wider or broader portions of an inclusive structure. |
spore |
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STRUCTURE |
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A simple, usually unicellular, sometimes oligocellular propagule derived by meiotic division of a diploid (2n chromosomes) sporocyte within a sporangium, thus of haploid (n chromosomes) genetic constitution. A spore constitutes the first ontogenetic stage of a gametophytic generation and gives rise to a usually multicellular gametophyte upon germination. Though technically present in seed-bearing plants, by itself it is descriptively significant only in those taxa that do not produce seeds. |
corolla tube 1 |
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STRUCTURE |
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A relatively narrow, fully connate portion of a sympetalous (gamopetalous) corolla proximal to a broader portion (limb) that comprises the distinct or connate distal portions of the petals; except in bisexual or staminate disc florets of Asteraceae (Compositae). |
megasporangium pl. megasporangia |
= macrosporangium (not recommended) |
STRUCTURE |
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A sporangium that produces megaspores. |
veinlet |
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STRUCTURE |
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A strand belonging to the ultimate (least in diameter) order of vasculature in a leaf or other basically laminar structure when that order consists of strands ending freely within areoles and/or connecting distally by pairs across areoles; absent in some taxa. See also costa (rib), lateral vein, midvein (midnerve, midrib), primary vein, secondary vein, tertiary vein, vein (nerve). |
peduncle |
<stalk, stipe (broad sense, not recommended) |
STRUCTURE |
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The common stalk, when present, of a compound inflorescence or first-order subunit thereof, or of a solitary flower that is deemed to represent an evolutionarily reduced compound inflorescence. |
archegonium pl. archegonia |
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STRUCTURE |
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A female gametangium; a multicellular fertile organ of a mature gametophyte within which female gametes (eggs, ova) are produced and fertilized; having a broad, bulbous base and a narrower distal neck. Technically present but highly reduced and of no descriptive significance in Magnoliophyta. |
embryotega pl. embryotegae, embryotegas |
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STRUCTURE |
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A small, hardened, lid-like portion of the testa (seed coat) at the micropyle of some seeds, detaching at germination. |
short-shoot |
= spur |
STRUCTURE |
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A first- or higher-order woody stem branch having relatively unelongated internodes, thus proximate nodes, and limited duration of growth, usually branching little if at all; often a main locus of flower production; usually more or less perpendicular to the axis that bears it and resembling a spur projecting from it; sometimes becoming more or less spinose after elongation ceases; esp. in Rosaceae. |
gynandrium pl. gynandria |
= column, gynostemium |
STRUCTURE |
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A central floral structure consisting of the partly to wholly fused (connate and adnate) androecium and gynoecium; esp. in Orchidaceae. |
massula pl. massulae |
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STRUCTURE |
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A body of coherent pollen grains, dispersed as a unit; esp. in Asclepiadaceae, Orchidaceae. |
antherozoid |
= spermatozoid; < sperm |
STRUCTURE |
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A motile male gamete, produced within an antheridium. |
prickle |
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STRUCTURE |
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Any unvascularized spine-like enation originating in the epidermis, cortex, or mesophyll of any shoot part. See also spine, thorn. |
androecium pl. androecia |
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STRUCTURE |
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The stamen(s), staminode(s), if any, and their ontogenetically associated structure(s), if any, of a single flower, taken collectively. |
neck (archegonial) |
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STRUCTURE |
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The distal narrowed portion of an archegonium above its bulbous base. |
jacket cell |
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STRUCTURE |
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Any of the cells forming the portion of an antheridial wall between the basal cells and the cap cell(s). |
limb 1 |
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STRUCTURE |
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A relatively broad portion of a syntepalous (gamotepalous) perianth, synsepalous (gamosepalous) calyx, or sympetalous (gamopetalous) corolla distal to a narrower tube, spreading outward or ascending from the tube, comprising the distinct or connate distal portions of the tepals, sepals, or petals; except in bisexual or staminate disc florets of Asteraceae (Compositae). |
spore body |
= sporocarp |
STRUCTURE |
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A multicellular structure that bears and more or less encloses several to (usually) many sporangia, the latter often aggregated into sori within it See also megasporocarp (macrosporocarp, not recommended), microsporocarp. |
spore case |
= sporangium |
STRUCTURE |
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A spore-producing organ; basically capsular, often supported by a slender stalk (sporangiophore), often lidded (operculate). In Bryophyta and Polypodiophyta, a distinct portion of the sporangial wall effects regular dehiscence at maturity. Spore cases or their equivalents are also present, but of little or no descriptive significance, in seed plants. |
viscidium pl. viscidia |
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STRUCTURE |
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A small, viscid, glandular body of rostellar origin that becomes connected with a pollinium caudicle, either directly or through an intervening stipe, by which the pollinium attaches to a pollinating insect; in Orchidaceae. |
ostiole |
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STRUCTURE |
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The distal aperture of a syconium (fig); in Ficus (Moraceae). |
ascidium pl. ascidia |
= pitcher, pitcher-blade |
STRUCTURE |
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An ascidiform (pitcher-shaped) leaf blade, sometimes operculate (lidded), usually carnivorous; esp. in Nepenthaceae, Sarraceniaceae. |
corolla tube 2 |
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STRUCTURE |
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The portion of the corolla of a bisexual or staminate disc floret proximal to the level of filament insertion; in Asteraceae (Compositae). |
megaspore |
= macrospore (not recommended) |
STRUCTURE |
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A female spore; a spore of the larger of two types produced by the sporophytes of a heterosporous taxon; produced in a megasporangium; giving rise upon germination to a megagametophyte. |
velamen pl. velamina |
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STRUCTURE |
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A thin, often chartaceous (papery, papyraceous) or pergamentaceous (parchment-like), outermost tissue layer of an aerial root; esp. in Orchidaceae. |