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actinodromous |
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venation |
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Having three or more primary veins that diverge radially from a point at or above the base of the blade and run toward the margin, reaching it or not. |
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pubescence |
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CHARACTER |
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Collective aspect of trichomes borne on the surface. Many of the terms traditionally used for describing pubescence have been defined and used in so many differing and often contradictory ways that they have become hopelessly ambiguous. This is attributable mainly to overdefinition within this portion of the traditional lexicon — that is, to highly arbitrary and widely variant restriction of a term's scope to some one detailed combination of trichome character states (shape, size, orientation, etc.). By derivation these are essentially general terms, really suited only for denoting overall aspect. The diversity actually encountered in nature defies comprehensive and unambiguous resolution into any limited suite of precisely specified, mutually exclusive, complex character states that can be associated with these terms, which are best used only in their general senses. Sometimes, such description will be sufficient in itself; more often, additionally or alternatively, the various attributes of the individual trichomes should be described. This is the only strategy that allows for full description of any possible condition, including the presence of more than one type of trichome. The various terms used for describing pubescence have never been semantically consistent; in some cases they refer to the trichomes themselves, while in others they apply to the bearing surface or structure; e.g., sericeous (the trichomes themselves are collectively silky) versus barbate (the structure is bearded). See also coating, indumentum (vesture). |
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indusiate |
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architecture |
sorus |
Having an indusium. |
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paraphysis pl. paraphyses |
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STRUCTURE |
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An elongate, multicellular, sterile structure borne between sporangia within a sorus; in Polypodiophyta. |
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drupelet |
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nominative |
fruit |
Diminutively drupe-like but derived from one of the simple, superior ovaries of an apocarpous flower, having a fleshy fruit wall and a hard seed (pyrene) within, a distinct constituent in an aggregate fruit; esp. in Rosaceae. |
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rachilla 2 var. rhachilla |
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STRUCTURE |
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A second-order axis in an inflorescence, especially the axis bearing the florets in a spikelet; esp. in Cyperaceae, Poaceae (Gramineae). |
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connate-perfoliate |
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architecture |
opposite laminar structures |
Having the bases in each pair fused and together encircling the bearing axis. See also amplexicaulous, perfoliate. |
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bundle scar |
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FEATURE |
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A smaller scar within the bounds of a leaf scar at the point where a vascular bundle traversed the abscission layer between stem and leaf. |
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intravaginal |
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insertion |
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Within the leaf sheath. |
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percurrent 2 |
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architecture |
tertiary laminar veins |
Perpendicular to and interconnecting adjacent parallel secondary veins, the secondary and tertiary veins together forming a scalariform pattern. |
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simple 2 |
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architecture |
trichome |
Unicellular and unbranched. |
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embryo |
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STRUCTURE |
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The rudimentary spermatophyte contained within a viable seed. |
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geminicolpate |
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architecture |
pollen grain |
Having four or more surficial grooves (colpi) disposed in pairs. |
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receptacular |
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insertion |
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Upon, arising from, or otherwise directly associated with the receptacle. |
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coronal |
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insertion |
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Upon or otherwise directly associated with the corona. |
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knee 1 |
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STRUCTURE |
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An abrupt bend in an axial or other elongate structure. |
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spathaceous 1 |
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architecture |
plant, inflorescence |
Bearing a spathe or spathes. |
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epipetalous |
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position |
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Upon the petals, or partially adnate thereto and apparently arising therefrom. |
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apex pl. apices |
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CHARACTER |
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Configuration of the uppermost, distal, or terminal portion of a structure, its extent determined somewhat subjectively in relation to the shape of the structure as a whole. The concept of apex varies from one descriptive context to another, since the apex is not a clearly delimited, morphologically distinct entity. The terms for describing apical condition are not strictly coordinate logically — some are more inclusive than others, some describe conditions involving what can be regarded as appendages, and some refer to the apex in a developmental as well as a strictly topological sense — and precise characterization may require using more than one descriptor. The semantic antecedent of some descriptors is "apex," whereas the antecedent of others is the structure as a whole (e.g., leaf ). |
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rhachilla |
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STRUCTURE |
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See rachilla. |
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syngenesious |
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fusion |
flower, androecium |
Having the anthers connate or coherent and forming a ring. |
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laminate |
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architecture |
foliaceous structure |
Having an expanded, more or less planate, distal portion (lamina or blade). |
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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. |
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exindusiate |
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architecture |
sorus |
Lacking an indusium. |
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nodule |
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STRUCTURE |
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A small nodiform (gongylodate, gongyloid, knob-shaped, knot-shaped) segment or protrusion; esp. in roots of Fabaceae (Leguminosae) and harboring nitrogen-fixing bacteria. |
