petiole |
< stalk, stipe (broad sense, not recommended) |
STRUCTURE |
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The stalk, when present, of a leaf. |
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. |
calyculus 2 pl. calyculi |
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STRUCTURE |
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Collectively the bractlets (bracteoles) sometimes subtending (beneath or outside) the involucre in a capitulum (head); in Asteraceae (Compositae). |
operculum pl. opercula |
= lid |
STRUCTURE |
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A distal, cover-like portion of a structure whose main body is otherwise closed, transversely discontinuous with the main body around most of the circumference, or becoming partially or wholly separate by transverse dehiscence; as of an ascidium (pitcher), pollen grain, pyxis, or sporangium (spore case). |
androgynophore |
< stalk |
STRUCTURE |
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A stalk that rises above the level of perianth insertion and bears the free portions of both androecium and gynoecium from its summit; as in Passifloraceae. |
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. |
seta 2 pl. setae |
= bristle; > glochid, glochidium |
STRUCTURE |
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A trichome that is elongate, slender, more or less straight, terete, fine-pointed, and stiff. |
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). |
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. |
rib |
= costa; > 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. |
trabecula pl. trabeculae |
< septum |
STRUCTURE |
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A transverse wall or partition that fully or partially separates two chambers within a sporangium. |
first glume |
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STRUCTURE |
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The lower (proximal) or sometimes solitary small bract inserted at the base of a grass (Poaceae) spikelet, the second glume, when present, inserted immediately above (distal to) it. |
beaklet 2 |
= rostellum |
STRUCTURE |
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A sterile excrescent stigma lobe protruding between the anther and the functional stigma lobes of a column; sometimes forming one or more viscidia at pollinium maturity; esp. in Orchidaceae. |
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. |
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. |
thallus 2 pl. thalli |
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STRUCTURE |
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The main body of a gametophyte, bearing rhizoids, gametangia (antheridia and/or archegonia), and/or gemmae cups; usually thin and more or less planate, inconspicuous, and growing appressed to or beneath the substrate surface; in Psilotophyta, Lycopodiophyta, Equisetophyta, Polypodiophyta. See also prothallus. |
calyptra pl. calyptrae |
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STRUCTURE |
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A distal hood- or lid-like portion that detaches as a unit from the remainder of the structure; esp. in some Papaveraceae the unopened calyx that separates from the rest of the flower at anthesis. |
squamule 1 |
= squamella; < scale |
STRUCTURE |
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A diminutive squama (lepis). |
primary axis |
> ray |
STRUCTURE |
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A main or first-order axis within any specified, uniformly delimited structural context. |
primary root |
> taproot |
STRUCTURE |
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The one, central root directly basal to a shoot, developing directly from the embryonic radicle; the first-formed root of a plant, being the only one truly central in nature (i.e., belonging to the original central axis of the plant). All other roots of a plant develop subsequently and are lateral in nature. The primary root may be permanently dominant, developing into a taproot; otherwise it may be transitory or become functionally subordinate, with secondary and/or adventitious roots becoming dominant. |
knee 1 |
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STRUCTURE |
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An abrupt bend in an axial or other elongate structure. |
pollen |
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STRUCTURE |
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Collectively, the spores or grains produced within the thecae of anthers, each containing a very small microgametophyte (or its evolutionary homologue); serving as disseminules from which microgametes are released after transport to a receptive micropylar pollen droplet (in Pinophyta) or stigma (in Magnoliophyta) by a variety of vectors, notably wind, water, insects, bats, and birds. |
limb 2 |
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STRUCTURE |
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The portion of the corolla of a bisexual or staminate disc floret distal to the level of filament insertion; in Asteraceae (Compositae). |
hood |
= cucullus |
STRUCTURE |
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A hood-shaped structure or component, esp. in an inflorescence or flower. |
microphyll |
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STRUCTURE |
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A small, lateral, leaf-like enation that, evolutionarily, is not a true leaf, i.e., whose vasculature, if any, consists of only a single median strand not ontogenetically integral with the vasculature of the bearing stem and not associated with leaf gaps in the stele of the stem; in Bryophyta, Psilotophyta, Lycopodiophyta, Equisetophyta. |