L., Sp. Pl. 518.1753 Prostrate herb, usually less than 1 m tall, but occasionally to 2 m or more when undisturbed; stems weakly ribbed, sparsely setose and armed with sharp spines. Leaves bipinnate with (1) 2 closely spaced pairs of pinnae, the pinnae mostly 3.5-6.5 cm long; leaflets in 10-20 pairs per pinna, sensitive, folding upon disturbance, oblong, 3-12 mm long, l-2 mm wide, glabrous, ciliate. Flowers dense, globular, pink clusters (congested racemes) on peduncles 1-2.5 cm long; floral bracteoles linear-lanceolate or linear-oblanceolate, setose; rachis elongating in fruit; calyx nearly obsolete; corolla funnelform, 1-2 mm long; stamens 4, ca 7 mm long; style sharp at apex, +/- equaling stamens. Legumes brown, oblong, mostly 3- or 4-seeded, equally notched on both sides, glabrous but with multidirectional setae on lateral margins. Croat 12712, 12813. Very abundant in the Laboratory Clearing; rare else where in clearings. Flowers and fruits principally from November to April.