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cross-vein |
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STRUCTURE |
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A relatively short, secondary or higher-order vein that runs directly between two veins of the next lower order, intersecting them more or less perpendicularly. |
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prophyll(um) pl. prophylls, prophylla |
= bracteole, bractlet; < bract |
STRUCTURE |
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A second- or higher-order bract within, and subtending some portion of, an aggregate branching structure, especially when subtending a flower. |
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rhizophore |
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STRUCTURE |
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A stem branch that bears no leaves and from which roots eventually arise; esp. in Selaginellaceae. |
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sporangiophore |
< stalk |
STRUCTURE |
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A stalk that bears one or more sporangia. |
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toothlet |
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STRUCTURE |
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A diminutive tooth (dens). See also sawtooth, sawtoothlet, scallop (crena), scalloplet (crenule). |
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lip |
= labium; > labellum |
STRUCTURE |
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Any substructure that resembles a lip, especially a portion of a perianth, calyx or corolla. |
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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). |
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adventitious root |
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STRUCTURE |
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A root that arises laterally from some part of a shoot, often from the lower portion of a main stem. |
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articulation |
= joint |
STRUCTURE |
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A distinct, relatively narrow zone of demarcation between adjacent main portions of an elongate structure, often thicker than the rest of the structure and sometimes a site of eventual abscission. |
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cilium 1 pl. cilia |
> capillus, hair; >< trichome |
STRUCTURE |
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A hair-like trichome or other surficial process. |
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sperm |
> antherozoid, spermatozoid |
STRUCTURE |
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A male gamete. |
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plantlet |
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STRUCTURE |
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A juvenile, complete plant produced asexually by budding, as from the leaf margin in some Kalanchoë (Crassulaceae); this term is usually applied only while such vegetatively produced offspring remain attached to the plant of origin. |
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flagellum pl. flagella |
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STRUCTURE |
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A very slender whip-like structure that extends from the main body of an antherozoid and, by active undulation, propels the cell through a liquid medium. |
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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). |
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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. |
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carina 1 pl. carinae |
= keel |
STRUCTURE |
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An elongate, median longitudinal ridge that is basically triangular in transverse section and resembles the keel of a boat; esp. in leaf blades and sheaths, glumes, lemmata, paleae, sepals, petals. |
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pinna pl. pinnae |
< leaflet |
STRUCTURE |
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One of the first-order divisions or leaflets of a pinnate frond; in Polypodiophyta. See also pinnule. |
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fertile frond |
< spore leaf, sporophyll |
STRUCTURE |
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A frond that bears sporangia; in Polypodiophyta. See also sterile frond (trophophyll). |
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mericarp |
= coccus |
STRUCTURE |
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One of the segments of a dehisced schizocarp; usually one-seeded and itself indehiscent. |
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division |
? lobe, segment |
STRUCTURE |
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Any generally convex, major peripheral protrusion or component sector that is delimited by concavities in the surface or margin and that is not proximally distinct from the remainder of the whole. |
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sporangium pl. sporangia |
= spore case |
STRUCTURE |
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A spore-producing organ; basically capsular, often supported by a slender stalk (sporangiophore), often operculate (lidded). In Bryophyta and Polypodiophyta, a distinct portion of the sporangial wall effects regular dehiscence at maturity. Sporangia or their equivalents are also present, but of little or no descriptive significance, in seed plants. |
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involucel |
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STRUCTURE |
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One or more closely proximate whorls of bractlets (bracteoles, prophylls) immediately subtending (below or outside) a subordinate portion of an inflorescence that is subtended as a whole by an involucre, the bractlets often leaf-like, sometimes petaloid. |
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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. |
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cilium 2 pl. cilia |
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STRUCTURE |
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A motile hair- or whip-like structure extending from the surface of a cell. |
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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. |
