Slender herbs or subshrub, prostrate or ascending from a somewhat woody base, the branchlets terete, glabrous or pubescent. Leaves moderate or moderately small, bipinnate, the pinnae 2-4 (normally 3) pairs opposite on the rachis, the leaflets many (12-40) pairs per pinna; petiole slender, 1-2 cm. long, pubescent or gla-brous, eglandular; rachis about as long as the petiole, eglandular, terminally apicu-late; pinnae mostly 2-4 cm. long, moderately remote, the axis somewhat alate; leaflets linear-oblong, 3-5 mm. long and 1-2 mm. wide, obtuse apically, obliquely rounded basally, usually glabrous except for a ciliate margin, the venation promi-nent below but remote; stipules ovate or lanceolate, about 4-5 mm. long, promi-nently longitudinally striate-nerved, subpersistent. Inflorescence of solitary, axillary, pedunculate heads; peduncles elongate, up to 6 cm. long in age, usually minutely 1-to few-bracteate near or above the middle; heads globose to briefly oblong, bearing dimorphic flowers; floral bractlets lanceolate or oblanceolate, about 2 mm. long, ciliate or glabrous. Flowers of 2 (3?) types, the few lower ones of head unisexual and with conspicuous petaloid stamens or staminodia; upper flowers without petaloid stamens or staminodia, usually perfect (occasionally with pistil aborted), sessile, yellow; calyx cupulate-funnelform, about 2 mm. long in perfect flowers, somewhat shorter in basal flowers, prominently 5-lobed, the lobes usually ciliate; corolla funnelform, about 3 mm. long in perfect flowers, somewhat shorter in basal flowers, glabrous, 5-lobate, the lobes about equalling the imperfectly closed tube; stamens (or staminodia) usually 10, glabrous, 5-6 mm. long; ovary glabrous, subfusiform, the style stout and about equalling the stamens. Legume broadly oblong, mostly 2-3 cm. long and 1 cm. wide or wider, flat, rounded apical-ly and briefly mucronate, substipitate basally, 2-valved, few-seeded, glabrous, the seeds transverse and slightly oblique.
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