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. |
androecium pl. androecia |
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STRUCTURE |
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The stamen(s), staminode(s), if any, and their ontogenetically associated structure(s), if any, of a single flower, taken collectively. |
pyrene 2 |
= stone |
STRUCTURE |
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The hard seed of a drupelet; esp. in Rosaceae. |
microsporangium pl. microsporangia |
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STRUCTURE |
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A sporangium that produces microspores. |
velum pl. vela |
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STRUCTURE |
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A membranous adaxial flap or fold of vegetative tissue wholly or partly covering the sporangial cavity of a sporophyll; in Isoëtaceae. |
spathe |
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STRUCTURE |
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A usually relatively large, sometimes showy, foliose bract subtending and sometimes partially enclosing an inflorescence, esp. a spadicate one; in Liliidae (monocotyledons). |
lenticel |
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STRUCTURE |
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A specialized, anatomically distinct structure within the periderm of a stem, consisting of comparatively spongy, sometimes suberized tissue distinct from others of the periderm; extending radially through the periderm and visible as a circular to elongate discontinuity in the color, texture, and/or relief of the outer surface of the stem; serving as a conduit for gas exchange between the stem interior and the atmosphere. |
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. |
phylloclade |
= cladode, cladophyll |
STRUCTURE |
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A stem segment that functions as a leaf; often more or less compressed. |
archegonium pl. archegonia |
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STRUCTURE |
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A female gametangium; a multicellular fertile organ of a mature gametophyte within which female gametes (eggs, ova) are produced and fertilized; having a broad, bulbous base and a narrower distal neck. Technically present but highly reduced and of no descriptive significance in Magnoliophyta. |
thorn |
= spine |
STRUCTURE |
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Any sharp, stiff, simple or branched, woody appendage having vascular tissues confluent with those of the bearing structure. "Spine" is often preferred when the appendage is homologous with a leaf or stipule, and "thorn" when it is homologous with a branch. See also prickle. |
wood |
= xylem |
STRUCTURE |
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The water-conducting and usually main supporting tissue of a plant or portion thereof, characterized by the presence of tracheary elements (tracheids and sometimes vessel elements); the lignified tissue of a plant or component structure, composed almost entirely of secondary tissue, i.e., that derived by secondary or lateral growth from a cambium in structures a season or more old. As commonly used, the term wood generally refers only to secondary xylem, which constitutes the bulk of a mature woody stem, but it properly refers also to primary xylem, wherever found. See also sapwood, heartwood. |
primocane |
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STRUCTURE |
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A biennial or perennial stem before it has begun flowering, when the latter does not occur until at least its second season of growth; esp. in Rubus (Rosaceae). |
mucro pl. mucrones, mucros |
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STRUCTURE |
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A short, hard, apical point that is a continuation of vascular tissue. See also apiculum. |
cilium 1 pl. cilia |
> capillus, hair; >< trichome |
STRUCTURE |
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A hair-like trichome or other surficial process. |
pollinium pl. pollinia |
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STRUCTURE |
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A mass of coherent pollen grains disseminated as a unit by adhering to a pollinating insect, representing the entire content of a single theca or of fused thecae; often distally attenuate to a sterile caudicle (translator arm), which may attach to a viscidium, either directly or through an intervening stipe; esp. in Asclepiadaceae, Orchidaceae. |
floral cup 1 (broad sense) |
= floral tube, hypanthium (broad sense) |
STRUCTURE |
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A complex structure comprising fused portions of the perianth and/or androecium of a flower, sometimes also including receptacular tissue; surrounding and wholly, partly, or not at all adnate to the gynoecium; subdivided morphologically into casing, collar and/or neck; sometimes bearing free distal portions of the constituent structures. |
microspore |
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STRUCTURE |
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A male spore; a spore of the smaller of the two types produced by the sporophytes of a heterosporous taxon; produced in a microsporangium; giving rise upon germination to a microgametophyte. |
adventitious bud |
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STRUCTURE |
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A vegetative or floral bud that arises directly from a root or from some site on a shoot other than a leaf axil or stem apex. |
pseudopetiole |
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STRUCTURE |
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A distinctly constricted, more or less stalk-like, proximal portion of a leaf, evolutionarily derived from the blade, the original petiole reduced to the point of absence or vestigiality; esp. in Poaceae (Gramineae). |
beard |
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STRUCTURE |
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A growth of relatively long, erect, flexible, capillary trichomes from one or more limited sectors of a structure's surface. |
replum pl. repla |
< dissepiment, septum |
STRUCTURE |
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The persistent wall or partition that separates the two locules of a silicle or silique. |
epicalyx pl. epicalyces |
= calyculus |
STRUCTURE |
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A whorl of bracts immediately subtending (beneath or outside) a calyx. |
phyllode |
= phyllodium |
STRUCTURE |
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A leaf deemed to consist entirely or almost entirely of tissues evolutionarily derived from the petiole, all or a distal portion of which has become expanded and blade-like, the original blade reduced to the point of absence or vestigiality. |
sawtoothlet |
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STRUCTURE |
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A diminutive sawtooth. See also scallop (crena), scalloplet (crenule), tooth (dens), toothlet. |