isthmus |
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STRUCTURE |
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A narrower portion connecting two wider or broader portions of an inclusive structure. |
sorus pl. sori |
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STRUCTURE |
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A cluster of sporangia borne upon a fertile frond, usually on its abaxial surface; often covered during maturation by a protective membrane, the indusium, that is an outgrowth from the epidermis; in Polypodiophyta. |
torus 2 pl. tori |
= receptacle |
STRUCTURE |
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The short, expanded, compound axial structure surmounting a peduncle and basal to two or more flowers, or to the florets of a capitulum (head) in Asteraceae (Compositae), where it may bear paleae (receptacular bracts), scales, bristles, trichomes, or subulate enations, and may be smooth or variously pitted (alveolate, foveolate). |
crista pl. cristae |
= crest |
STRUCTURE |
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A laterally elongate, relatively thin, irregular or notched, apical protrusion. |
internode |
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STRUCTURE |
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Any portion of a stem between two successive nodes. |
epidermal cell |
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STRUCTURE |
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Any of the unspecialized cells of an epidermis; i.e., any other than stomatal guard cells or cells directly associated with trichomes. While the latter specialized cells are also properly epidermal cells, they are treated separately for descriptive purposes and, for the sake of convenience, use of the general term is restricted to the unspecialized cells that constitute the bulk of an epidermis. |
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. |
bristle 1 |
= arista, awn, seta |
STRUCTURE |
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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). |
thallus 1 pl. thalli |
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STRUCTURE |
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The vegetative portion of a shoot when not differentiated into stem and leaves; esp. in Lemnaceae. |
pistillode |
= pistillodium |
STRUCTURE |
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Any sterile structure deemed to represent a modified pistil, homology being inferred on the basis of structural similarity, ontogeny, and/or position; sometimes nectariferous, sometimes connate with others or adnate to other floral structures. |
filament |
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STRUCTURE |
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The stalk, when present, of a stamen, clearly differentiated from and bearing at its summit an anther. |
scape |
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STRUCTURE |
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A leafless, essentially naked, inflorescence-bearing stem (or peduncle) arising directly from a caudex or rhizome, its point of insertion slightly beneath, at, or slightly above the substrate surface. |
pale 2 |
= palea, palet |
STRUCTURE |
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The upper or distal of the (usually) two distinctive bracts immediately subtending the flower in a grass (Poaceae) spikelet. |
twig |
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STRUCTURE |
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The terminal portion of an ultimate branch of a woody stem, representing the most recent increment of growth and bearing or having borne the current or most recent increment of leaves. See also branchlet. |
seta 1 pl. setae |
= arista, awn, bristle |
STRUCTURE |
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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). |
bladder |
= ampulla |
STRUCTURE |
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A small, membranous, hollow, flask-shaped, insectivorous structure borne on a submerged leaf; esp. in Lentibulariaceae. |
petal |
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STRUCTURE |
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One of the one or more constituent members of a corolla; colored and showy in many taxa, inconspicuous in size and/or color in others; may be distinct or else connate with one or more others, and/or may be free or else adnate to one or more other floral structures. |
capillus pl. capilli |
= hair; > glochid, glochidium; < cilium, trichome |
STRUCTURE |
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A hair-like trichome. |
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. |
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). |
beak 1 |
= rostrum |
STRUCTURE |
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A relatively long, tapering, more or less rigid and pointed enation or termination. |
antheridium pl. antheridia |
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STRUCTURE |
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A male gametangium; a multicellular fertile organ of a mature gametophyte within which male gametes (antherozoids, spermatozoids) are produced and from which they are discharged, in some taxa forcibly, through a pore. Technically present but highly reduced and of no descriptive significance in Magnoliophyta and part of Pinophyta. |
rostrum 1 pl. rostra |
= beak |
STRUCTURE |
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A relatively long, tapering, more or less rigid and pointed enation or termination. |
flesh |
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STRUCTURE |
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Tissue that is fairly firm and dense, juicy or at least moist, and easily cut. |
trabecula pl. trabeculae |
< septum |
STRUCTURE |
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A transverse wall or partition that fully or partially separates two chambers within a sporangium. |