Tree, to 25 m tall; trunk weakly buttressed, to 45 cm dbh; outer bark unfissured, rough, hard, thin; inner bark reddish-brown, granular; young branches, petioles, rachises, and pinnular rachises rufous-tomentose; sap with an indistinct odor. Leaves bipinnate with 10-25 pairs of opposite pinnae; petioles 1.5-3 cm long, swollen basally, bearing a small, sessile gland ca 0.5 mm wide just above the pulvinus; stipules minute, caducous; rachis to 25 cm long, ridged along the center of the upper surface, with a similar gland at each node; pinnular rachis 4-10 cm long with 1 to several glands at terminal nodes; leaflets in 50-70 pairs per pinna, linear-oblong, less than 5 mm long and 0.8 mm wide, glabrous above, rufous-puberulent below, the midrib eccentric. Inflorescences rufous-tomentulose, axillary, in groups of 3-8; peduncles 1-4 cm long; heads short-spicate, appearing globular with the axis ca 2.5 mm long; bracts miniscule; flowers sessile to subsessile, green with white anthers; calyx turbinate, ca 2.5 mm long, the teeth 5, obtuse to acute, ca 1 mm long; corolla 2.5-5 mm long, the 5 segments acute, densely sericeous outside, glabrous inside; stamens 10, to 10 mm long, united at base into a short tube (if the tube extends nearly the entire length of the stamens, the stamens reduced to staminodia). Legumes reniform, 2-2.5 cm wide, curved into an overlapping circle to 5 cm diam, flat, reddish-brown, glabrous; seeds ellipsoid-to triangular-compressed, 6-8 mm long, smooth, brown, ringed on the largest circumference with a lighter area. Croat 14986, Wilson 130, Woodworth & Vestal 688. Mexico and Guatemala to Brazil. In Panama, scattered and possibly cultivated; known from tropical moist forest in the Canal Zone and Panama, from premontane wet forest in Chiriqui, and from tropical wet forest in Panama.