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. |
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. |
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. |
column 1 |
= gynandrium, gynostemium |
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. |
chaff 1 |
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STRUCTURE |
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Collectively, the paleae (pales, palets) sometimes borne on the receptacle of a capitulum (head) in Asteraceae (Compositae). |
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). |
bractlet 1 |
= bracteole; < bract |
STRUCTURE |
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A diminutive bract, or a bract that is smaller than others present. |
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. |
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. |
spadix pl. spadices |
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STRUCTURE |
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A thick, fleshy, primary inflorescence axis bearing sessile flowers more or less sunken into its surface, the whole subtended and sometimes partially enclosed by a specialized bract, the spathe; esp. in Araceae. |
corolla tube 2 |
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STRUCTURE |
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The portion of the corolla of a bisexual or staminate disc floret proximal to the level of filament insertion; in Asteraceae (Compositae). |
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. |
stem |
> cane, culm |
STRUCTURE |
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The entire axial system of a shoot, or a component, primary or higher-order (branch) axis of the shoot; differentiated anatomically and morphologically into nodes and internodes, from the former of which it branches exogenously and bears leaves, bracts, and/or inflorescences; usually growing above ground level, but sometimes structurally and functionally specialized and growing underground (e.g., rhizome, tuber) or upon the surface of the ground (e.g., stolon). Although sometimes phenotypically distinctive and often treated separately for descriptive purposes, the axial system of an inflorescence, excluding pedicels or parts of them in some cases, is properly stem in the above general sense. |
pseudobulb |
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STRUCTURE |
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An enlarged internode of an aboveground stem, storing water and photosynthate, resembling a bulb; esp. in Orchidaceae. |
lemma pl. lemmata, lemmas |
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STRUCTURE |
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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. |
galea pl. galeae, galeas |
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STRUCTURE |
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A galeate (galeiform, helmet-shaped) sepal or petal in a zygomorphic calyx or corolla, differing markedly in shape from and sometimes partially enclosing the other sepals or petals. |
petiolule |
< stalk |
STRUCTURE |
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The stalk, when present, of a leaflet, analogous to the petiole of a leaf. |
cucullus pl. cuculli |
= hood |
STRUCTURE |
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A cucullate (cuculliform) structure or component, esp. in an inflorescence or flower. |
theca pl. thecae |
= pollen sac |
STRUCTURE |
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Any of the one, two or four ontogenetically distinct, pollen-producing sectors (microsporangia) of an anther. In some taxa the walls between pairs of adjacent thecae break down as an anther approaches maturity, the mature anther thus ultimately containing half as many locules as thecae. |
squamule 2 |
= squamella; < scale |
STRUCTURE |
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A small, dry bract borne on the compound receptacle (torus) of a capitulum (head); in Asteraceae (Compositae). |
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. |
column 2 |
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STRUCTURE |
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A fused androecium (connate stamens) closely surrounding but free from the gynoecium; esp. in Malvaceae. |
knee 1 |
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STRUCTURE |
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An abrupt bend in an axial or other elongate structure. |
chaff 2 |
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STRUCTURE |
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Collectively, the glumes, lemmata, and paleae of mature spikelets; in Poaceae (Gramineae). |