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. |
gynophore |
= hypogynium; < 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. |
ochrea |
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STRUCTURE |
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See ocrea. |
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. |
rhachilla |
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STRUCTURE |
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See rachilla. |
petiole |
< stalk, stipe (broad sense, not recommended) |
STRUCTURE |
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The stalk, when present, of a leaf. |
needle |
< leaf, macrophyll (not recommended), megaphyll |
STRUCTURE |
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A relatively stiff, compressed-acerose leaf; in Pinophyta. |
primary axis |
> ray |
STRUCTURE |
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A main or first-order axis within any specified, uniformly delimited structural context. |
wall (fruit, ovary, pollen, spore) |
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STRUCTURE |
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The exterior layer of tissue(s) enclosing anatomically distinct interior tissues and sometimes fluid and/or one or more cavities. |
scale 2 |
> lepis, squama, squamella, squamule; < trichome |
STRUCTURE |
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A planate trichome. |
tuber |
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STRUCTURE |
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An enlarged, basically subterranean stem segment or thallus outgrowth containing a high proportion of storage tissue and functioning as a perennating and often vegetatively propagative structure. |
leaf 2 pl. leaves |
= microphyll |
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 Psilotophyta, Lycopodiophyta, Equisetophyta. |
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. |
accessory cell |
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STRUCTURE |
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One of the cytologically distinctive epidermal cells that are sometimes present in a stomate and that surround and are regularly oriented in relation to the guard cells. |
gynostegium pl. gynostegia |
< corona |
STRUCTURE |
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An androecial corona, typically consisting of distinct hood- and/or horn-shaped enations that rise above the anthers; esp. in Asclepiadaceae. |
antheridium pl. antheridia |
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STRUCTURE |
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A male gametangium; a multicellular fertile organ of a mature gametophyte within which male gametes (antherozoids, spermatozoids) are produced and from which they are discharged, in some taxa forcibly, through a pore. Technically present but highly reduced and of no descriptive significance in Magnoliophyta and part of Pinophyta. |
ocrea pl. ocreae var. ochrea |
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STRUCTURE |
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A tubular sheath that encircles a stem at a node, subtending a petiole; thought to have arisen evolutionarily by lateral fusion of two stipules; in Polygonaceae. |
rhachis |
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STRUCTURE |
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See rachis. |
membrane |
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STRUCTURE |
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A relatively thin layer of tissue that covers or separates other, different tissue(s) and/or empty space(s). |
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. |
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. |
shoot 2 |
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STRUCTURE |
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A vascularized axis that is differentiated into nodes and internodes and that branches exogenously from the former, together with any non-axial structures borne from it. |
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. |
tertiary vein |
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STRUCTURE |
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A strand belonging to the third order of vasculature in a leaf or other basically laminar structure, except when that is the ultimate order (consisting of veinlets); branching from a primary or secondary vein. See also costa, lateral vein, primary vein, rib, secondary vein, veinlet. |
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. |