Flora of North America Glossary

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Term Synonyms Category Limitation Definition
archegonium pl. archegonia STRUCTURE 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.
arching = recurved orientation Curving backward or downward.
architecture CHARACTER Composite structural configuration as to type, orientation, symmetry, insertion, position, fusion, presence, number, relative size, shape, texture, differentiation, and/or derivation of components and features. Overlaps conceptually with habit.
arcuate 1 course Curving more or less regularly in one direction.
arcuate 2 plane shape Elongate and more or less regularly curved from one end to the other, one side convex, the opposite concave.
areola 1 pl. areolae = areole STRUCTURE Any distinctive surficial discontinuity of generally circular outline, whether concave, flush, or convex; when protuberant, sometimes bearing trichomes or spines, as in some Cactaceae. This term is used only when such entities are deemed structurally distinctive enough to merit description in their own rights, rather than as aspects of the surface.
areola 2 pl. areolae = areole STRUCTURE foliaceous structure Any distinguishable laminar portion bounded on all sides by anastomosing veins and not traversed or dissected by any vasculature other than veinlets.
areolate relief Having numerous, small, irregularly disposed, transversely angular, shallow depressions or low protrusions overall.
areole 1 = areola STRUCTURE Any distinctive surficial discontinuity of generally circular outline, whether concave, flush, or convex; when protuberant, sometimes bearing trichomes or spines, as in some Cactaceae. This term is used only when such entities are deemed structurally distinctive enough to merit description in their own rights, rather than as aspects of the surface.
areole 2 = areola STRUCTURE foliaceous structure Any distinguishable laminar portion bounded on all sides by anastomosing veins and not traversed or dissected by any vasculature other than veinlets.
aril 1 (broad sense) > arillode, arillus STRUCTURE An appendicular structure that wholly or partly envelops a seed and is produced from or a modification of the funicle, raphe, outer integument, or (in some Pinophyta) a subtending involucre; usually fleshy or pulpy, sometimes spongy or tufted-capillate, often brightly colored.
aril 2 (strict sense) = arillus STRUCTURE An appendicular structure that wholly or partly envelops a seed and is an outgrowth from the funicle or raphe, and thus is ontogenetically derived from the placenta; usually fleshy or pulpy, sometimes spongy or tufted-capillate, often brightly colored.
arillate architecture seed Having an aril.
arillode < aril (broad sense) STRUCTURE A "false" aril; an appendicular structure that wholly or partly envelops a seed and is produced from or a modification of the outer integument or (in some Pinophyta) a subtending involucre, but not from the funicle or raphe, and thus is not ontogenetically derived from the placenta; usually fleshy or pulpy, sometimes spongy or tufted-capillate, often brightly colored.
arillus pl. arilli = aril (strict sense); < aril (broad sense) STRUCTURE An appendicular structure that wholly or partly envelops a seed and is an outgrowth from the funicle or raphe, and thus is ontogenetically derived from the placenta; usually fleshy or pulpy, sometimes spongy or tufted-capillate, often brightly colored.
arista pl. aristae = awn, bristle, seta STRUCTURE A slender, more or less straight and stiff, fine-pointed, terminal or subterminal appendage or prolongation, sometimes a continuation of the bearing structure's central primary vein, as on a glume, lemma, or palea in Poaceae (Gramineae).
aristate 1 = awned, bristled apex Bearing one or more aristae (awns, bristles, setae).
aristate 2 apex pappus scale Terminating in one or more awn- or bristle-like appendages.
aromatic odor Having a distinct odor; usually restricted to pleasant odors.
arrangement CHARACTER Disposition of equivalent structures with respect to one another (positions/insertions and/or orientations, regarded collectively) within some explicit or implicit standard context. Overlaps conceptually with habit, insertion, orientation, position, and shape.
arrowhead-shaped 1 = sagittate base laminar structure Having two retrorse, generally triangular lobes, one to either side.
arrowhead-shaped 2 = sagittate plane shape Generally triangular, tapering gradually from the base to an acute apex, the base with a relatively large, acute, retrorse lobe to either side; like the outline of the broad lateral face of an arrowhead.
articulate(d) = jointed architecture Elongate with one or more distinct, relatively narrow zones of demarcation between adjacent main portions of the whole, these articulations (joints) often thicker and sometimes sites of eventual abscission.
articulation = joint STRUCTURE A distinct, relatively narrow zone of demarcation between adjacent main portions of an elongate structure, often thicker than the rest of the structure and sometimes a site of eventual abscission.
ascending = assurgent, upcurved orientation lateral structure Spreading at the base and then curving upward or forward, the distal portion more or less parallel to the bearing structure.
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