stomate |
= stomatal apparatus, stoma (broad sense) |
STRUCTURE |
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A localized functional epidermal unit consisting of a microscopic pore and two encircling specialized cells, the guard cells, which, through changes of turgor pressure in response to environmental conditions, regulate the size of the pore and thus the rates of transpiration and gas exchange through it; the whole surrounded or not by associated, cytologically distinctive epidermal cells, the subsidiary or accessory cells, which, when present, are regularly oriented in relation to it. |
cupule |
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STRUCTURE |
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A cup-like structure inserted at the base of a fruit, partially enclosing it or not; composed of a persistent, usually dried, sometimes hardened involucre, perianth, or portion thereof, the constituent parts often coalescent, yielding a unitary structure. |
mesocarp |
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STRUCTURE |
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The middle tissue layer of the pericarp of a fruit. |
vasculature |
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STRUCTURE |
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The vascular strands of all orders (veins and veinlets) in a particular part or organ, regarded collectively; consisting of conducting tissues (xylem, phloem) and associated supporting and enclosing tissues (e.g., sclerenchyma, collenchyma). |
barb 1 |
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STRUCTURE |
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Any relatively short, stiff, sharp, acutely inserted or bent, antrorse or retrorse, terminal or lateral appendage. |
torus 1 pl. tori |
= receptacle |
STRUCTURE |
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The relatively short, simple, axial structure surmounting a pedicel and basal to the flower, usually broader than the pedicel. |
epicarp |
= exocarp |
STRUCTURE |
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The outermost tissue layer of a pericarp. |
bud |
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STRUCTURE |
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A rudimentary, unexpanded stem, stem branch, inflorescence, inflorescence branch, or flower, or a combination thereof, in a resting state; enveloped or not by subtending protective scales. |
neck (archegonial) |
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STRUCTURE |
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The distal narrowed portion of an archegonium above its bulbous base. |
elater 1 |
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STRUCTURE |
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An elongate cell with a helical, hygroscopic thickening in its wall, contained within a sporangium, expanding and contracting with changes in humidity and aiding dispersal of the spores; esp. in Hepaticae. |
bole |
= trunk; < main stem, primary stem |
STRUCTURE |
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The relatively stout, columnar, main stem of a distinct aboveground portion of a tree. |
hypogynium pl. hypogynia |
= gynophore; < stalk, stipe (broad sense, not recommended) |
STRUCTURE |
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The basal portion of an ovary when constricted and stalk-like above the level of perianth insertion, bearing the main body of the pistil at its summit; in Cyperaceae. |
prickle |
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STRUCTURE |
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Any unvascularized spine-like enation originating in the epidermis, cortex, or mesophyll of any shoot part. See also spine, thorn. |
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. |
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. |
carina 2 pl. carinae |
= keel |
STRUCTURE |
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Collectively, the two relatively small, connate or coherent, abaxial (lower) petals that form the keel-like portion of a papilionaceous corolla. |
pneumatophore |
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STRUCTURE |
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A structurally and functionally specialized root serving as an aboveground aerating organ; found in some woody taxa of wet habitats, notably some mangroves. |
dropper |
= tuberoid |
STRUCTURE |
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An axial outgrowth that descends from a bulb and eventually forms a new bulb; esp. in Orchidaceae. |
mesochilium |
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STRUCTURE |
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The central portion of a labellum (lip) that has distinct proximal, distal, and central parts; in Orchidaceae. See also epichilium, hypochilium. |
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. |
disk |
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STRUCTURE |
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See disc. |
barb 2 |
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STRUCTURE |
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A trichome terminated by one or two small, relatively short, stiff, sharp, acutely reflexed appendages. |
pith |
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STRUCTURE |
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The central ground tissue of a stem or, when present, of a root, consisting of thin-walled parenchyma cells; distinct and more or less soft and spongy relative to the other tissues of the axis; sometimes partly or wholly degenerating after secondary growth has begun. |
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). |
epichilium |
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STRUCTURE |
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The distal portion of a labellum (lip) that has distinct proximal, distal, and sometimes also central parts; in Orchidaceae. See also hypochilium, mesochilium. |