costa pl. costae |
= rib; > midnerve (not recommended), midrib, midvein; >< lateral vein |
STRUCTURE |
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A primary vein of a laminar structure, having a longitudinal course, either medial or lateral, often prominent. See also secondary vein, tertiary vein, veinlet. |
flange |
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STRUCTURE |
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A relatively broad, circumferential rim or ridge that protrudes laterally. |
bark |
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STRUCTURE |
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The outermost portion of any shoot or root axis having secondary growth, consisting of all those tissues outside the vascular cambium; sometimes exhibiting zonation into inner, living bark and outer, dead bark; usually described only as to external appearance. |
lateral vein |
>< costa, primary vein, rib; > secondary vein |
STRUCTURE |
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A longitudinal primary vein (costa, rib) that runs to one side of the midline, or a secondary vein that runs toward the lateral margin. See also tertiary vein, veinlet. |
annulus 1 pl. annuli |
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STRUCTURE |
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A small ring-like protrusion from the strobilar stalk near its base and below the lowermost sporangiophores, sometimes bearing small sporangia; esp. in Equisetum. |
scale 1 |
< bract |
STRUCTURE |
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A basically dry, more or less appressed, diminutive bract. The choice of term as between the more general bract and the more restricted scale is sometimes problematic and, when so, often is dictated by custom according to the structure and taxon involved. |
stamen |
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STRUCTURE |
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A seed-plant organ that produces and releases pollen; usually comprising a stalk (filament) that bears a locular structure (anther) containing sporogenous tissue; however, the filament may be lacking and the anther sessile, or the stamen may be undifferentiated, the whole then consisting of microsporangia embedded in or borne upon the surface of a more or less planate body of sterile tissue; one of the constituent organs of a bisexual or a staminate flower; may be distinct or else connate with one or more others and/or may be free or else adnate with one or more other floral structures. |
prop root |
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STRUCTURE |
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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. |
macrostrobilus pl. macrostrobili (not recommended) |
= female cone, megastrobilus |
STRUCTURE |
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A strobilus (cone) whose fertile organs are all megasporophylls. |
perigynium 1 pl. perigynia |
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STRUCTURE |
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Two whorls of bracts, scales or setae immediately subtending the ovary, sometimes cupulate (cup-shaped) or ampulliform (flask-shaped, lageniform) and investing the fruit (achene); in Cyperaceae. |
receptacle 2 |
= torus |
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). |
gynostemium pl. gynostemia |
= column, gynandrium |
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. |
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. |
carpophore 1 |
< stalk |
STRUCTURE |
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The stalk supporting a sporocarp. |
rachilla 1 var. rhachilla |
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STRUCTURE |
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A second- or higher-order axis of a compound leaf blade, bearing higher-order rachillae, leaflets, pinnules and/or tendrils. |
coccus pl. cocci |
= mericarp |
STRUCTURE |
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One of the segments of a dehisced schizocarp; usually one-seeded and itself indehiscent. |
stilt root |
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STRUCTURE |
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A relatively stout or strong adventitious root arising from a woody stem branch and extending downward directly toward the substrate, within which it ultimately becomes anchored, thus supporting the branch of origin; as in some Ficus (Moraceae). |
trichome |
> bristle, capillus, glochid, glochidium, hair, lepis, scale, seta, squama, squamella, squamule; >< cilium |
STRUCTURE |
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Any superficial, unicellular or multicellular structure arising entirely from an epidermis. Unlike other epidermal enations or coverings, trichomes are cellular structures. |
annulus 2 pl. annuli |
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STRUCTURE |
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A row of protruding specialized sporangial wall cells that extends upward from the base of the sporangium and over its apex, thus forming an incomplete circumferential ring; esp. in Polypodiophyta. The inner and radial walls of the annular cells are markedly thickened and the structure functions as a spore-releasing and -disseminating mechanism as a result of differential stresses developed within the mature sporangial wall upon desiccation. |
scale 2 |
> lepis, squama, squamella, squamule; < trichome |
STRUCTURE |
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A planate trichome. |
shoot 1 |
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STRUCTURE |
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Collectively, all those portions of a plant body that are anatomically distinct from the root, the component axes differentiated into nodes and internodes, and branching exogenously from the former. |
perigynium 2 pl. perigynia |
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STRUCTURE |
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A phyllary (involucral bract) or palea (pale, palet) that fully encloses a cypsela; in Asteraceae (Compositae). |
labium pl. labia |
= lip; > labellum |
STRUCTURE |
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Any substructure that resembles a lip, especially a portion of a perianth, calyx or corolla; in Lamiaceae (Labiatae) sometimes restricted to the abaxial (lower) of the two corolla lips. |
bracteole 1 |
= bractlet; < bract |
STRUCTURE |
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A diminutive bract, or a bract that is smaller than others present. |
spore leaf |
= sporophyll; > fertile frond |
STRUCTURE |
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A leaf or homologous structure that bears sporangia See also megasporophyll (macrosporophyll, not recommended), microsporophyll. |