Botany Terms

Name Structure/ Category Description
Achene [Fruits] {type} A more or less small, dry fruit that does not split open at maturity (indehiscent), with a typically thin, close-fitting wall surrounding a single seed.
Acicular [Leaflets, Leaves] {shape} Very long and slender, gradually tapering to a point, like a needle; needle-shaped.
Acorn [Fruits] {type} A nut with a persistent, cup-like structure (cupule) attached at the base consisting of numerous partially fused, overlapping, dry bracts, as in oaks (Quercus).
Actinomorphic radially symmetrical -- used of organisms, organs, or parts capable of division into essentially symmetrical; halves by any longitudinal palne passing through the axis
Acuminate [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} Gradually tapering to a sharp point, forming concave sides along the tip.
Acute [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} Tapering to a pointed apex with more or less straight sides, the sides coming together at an angle of less than 90.
Adnate grown together, used especially of unlike parts
Adventitious (1) Structures or organs arising in a position that is unusual for their type, as roots originating on the stem.
Adventitious (2) [Roots] {type} Roots arising from any part of the plant (e.g. stem or leaf) other than the root system; usually growing laterally, often from the lower part of the main stem.
Aerial stem [Stems] {type} A prostrate to erect, above ground stem.