bristle 1 |
= arista, awn, seta |
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A slender, more or less straight and stiff, fine-pointed, terminal or subterminal appendage or prolongation, sometimes a continuation of the bearing structure's central primary vein, as on a glume, lemma, or palea in Poaceae (Gramineae). |
nucellus pl. nucelli |
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The distinct, genetically diploid tissue layer immediately surrounding the embryo sac of an ovule; often considered equivalent to a megasporangium wall. |
indusium pl. indusia |
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A protective membrane that is an outgrowth from the epidermis and covers a sorus during its maturation; in Polypodiophyta. |
lemma pl. lemmata, lemmas |
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The proximal bract of the (usually) two that immediately subtend the flower in a grass (Poaceae) floret; the other is the palea. |
unguis pl. ungues |
= claw |
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The abruptly much narrower proximal portion, when present, of a laminar structure, esp. a petal; of variable shape itself, but usually attenuate toward the base. |
bladder |
= ampulla |
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A small, membranous, hollow, flask-shaped, insectivorous structure borne on a submerged leaf; esp. in Lentibulariaceae. |
enation |
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STRUCTURE |
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A relatively small outgrowth from an otherwise regular boundary or surface of a larger structure. |
coma pl. comae, comas |
< tuft |
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A prominent single tuft of relatively long and slender, flexible, capillate trichomes; esp. from a seed, as in Asclepias (Asclepiadaceae). |
phyllopodium pl. phyllopodia |
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A stem-like axis composed of fused leaf bases; esp. in Arecaceae (Palmae), Musaceae. |
dyad |
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STRUCTURE |
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A pair of coherent pollen grains shed as a unit. |
gemma pl. gemmae |
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STRUCTURE |
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A vegetative propagule by which a gametophyte reproduces asexually; produced by a process analogous to budding, from a more or less cupulate specialized area (gemmae cup) on the surface of the plant body (thallus); in Psilotophyta, Lycopodiophyta, Equisetophyta, Polypodiophyta. |
knee 2 |
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STRUCTURE |
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An emergent portion of an otherwise normally submerged secondary root of a wetland tree, resembling a bent human knee. |
perianth tube |
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A relatively narrow, fully connate portion of a syntepalous (gamotepalous) perianth proximal to a broader portion (limb) that comprises the distinct or connate distal portions of the tepals. |
prop root |
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A relatively stout adventitious root arising from the lower portion of a main stem and extending outward and downward toward the substrate, within which it ultimately becomes anchored, thus buttressing the aboveground portion of the plant. |
rhizoid |
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STRUCTURE |
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Any structure that is similar to a root in appearance and function but that is not a true root ontogenetically and anatomically, especially one produced from a gametophyte thallus. |
subsidiary cell |
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One of the cytologically distinctive epidermal cells that are sometimes present in a stomate and that surround and are regularly oriented in relation to the guard cells. |
bristle 2 |
= seta; > glochid, glochidium; < trichome |
STRUCTURE |
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A trichome that is elongate, more or less straight, terete, fine-pointed, and stiff. |
blade |
= lamina |
STRUCTURE |
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The expanded, more or less planate, distal portion, when present, of a leaf, leaflet or bract. |
neck (archegonial) |
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STRUCTURE |
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The distal narrowed portion of an archegonium above its bulbous base. |
rostrum 1 pl. rostra |
= beak |
STRUCTURE |
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A relatively long, tapering, more or less rigid and pointed enation or termination. |
knee root |
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STRUCTURE |
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A specialized secondary root of a wetland tree, a portion of which projects above mean water level and appears to bend as a leg does at the knee, its distalmost portion being anchored in the substrate beneath the water. The knee of the root is commonly regarded as a conduit for gas exchange between root interior and atmosphere, a function whose need is posited on the basis of the highly anaerobic and saturated conditions prevailing in wetland substrates. |
pericarp |
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STRUCTURE |
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The portion of a fruit wall that is derived from the ovary wall; consisting of three more or less distinct tissue layers (exocarp or epicarp, mesocarp, and endocarp) that may or may not differ greatly in structure and/or function; the wall of a fruit, excluding any tissues of extra-ovarian (accessory) origin. |
vein |
= nerve; > costa, midnerve, midrib, midvein, rib |
STRUCTURE |
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A strand belonging to any except the ultimate (least in diameter) order of vasculature in a leaf or other foliaceous structure. See also lateral vein, primary vein, secondary vein, tertiary vein, veinlet. |
mamma pl. mammae |
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STRUCTURE |
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A rounded-conoidal protrusion, resembling the breast of a mammal. |
testa pl. testae |
= seed coat |
STRUCTURE |
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The outer protective layer of a seed, developed from the ovular integument(s). |