Pithecellobium Mart.

Trees or shrubs, unarmed or, less frequently, armed with stipular spines or thorns, the branchlets usually puberulent or tomentulose and lenticellate. Leaves small or large, except in very few species ("Cojoba") bipinnate, the pinnae 1 to several pairs opposite on the rachis; leaflets 1 to many pairs opposite on the pinnular rachis (except frequently basal pair alternate or one leaflet of pair aborted); petiole unwinged, usually short, rarely bearing a gland on the upper side; rachis similar to the petiole, generally bearing a gland at insertion of each pair of pinnae; pinnular rachis usually similarly glandular, the glands commonly cupulate; leaflets 2 to many per pinna, small or large, entire, usually inequilateral, seldom heavily pubes-cent above; stipules minute or of prominent spines or thorns. Inflorescence of 1 to several axillary or supra-axillary, lateral or subterminal, pedunculate (rarely sessile) heads or spikes; floral bracts minute or conspicuous. Flowers pentamerous, sessile or rarely pedicellate, almost invariably whitish; calyx campanulate to tubular, pubescent or subglabrous, valvate, shallowly dentate; corolla tubular to funnelform, generally elongate, valvate, frequently tomentulose on the 5 lobes; stamens many, united below into a staminal tube included in or exceeding the corolla; ovary glabrous or pubescent, sessile or stipitate. Legume moniliform, compressed or flat, subcircinate, arcuate or almost straight, normally dehiscent, the valves often twisting after dehiscence; seeds often imbedded in pulp.