Description:
Annual, erect or straggling herbs. Leaves paripinnately 4-foliolate; leaflets obovate or elliptic, mucronate at apex; stipules partly adnate to petiole, linear-lanceolate, very acute, ciliate, veined, persistent; stipels absent. Flowers axillary, apparently solitary and stalked; primary bracts ovate-lanceolate, biapiculate; secondary bracts similar but 2-fid; receptacle long and filiform, pedicel-like. Calyx membranous, filiform, 5-lobed: 4 upper lobes joined, lower one +/- free. Corolla yellow, usually with red nerves; standard rounded, shortly narrowed at base; wings free; keel beaked, incurved. Stamens 8 or 9, all joined; 4 or 5 anthers elongate and sub-basifixed, alternating with 4 or 5 short and versatile ones. Ovary subsessile, situated at base of receptacular tube, linear; ovules (1)2-4(-7); style filiform, very long, soon deciduous; stigma terminal, minute. Pod oblong or sausage-shaped, 1-6-seeded, somewhat constricted between seeds but not articulated, continuous inside, functionally indehiscent; walls thick and reticulate, developing below soil, having been pushed beneath by considerable lengthening, reflexing and stiffening of gynophore. Seeds irregularly ovoid or oblong; cotyledons thick and fleshy, rich in oil.
Distribution:
Species +/- 20, S America, 1: Arachis hypogaea L. the ground-nut, is widely cultivated throughout the tropics, and is occasionally found as an escape.
Source:
SSTA
Classification:
Add new comment