DC., Mém. Leg. 12:439.1826
Tree, to 8 m tall; branchlets, petioles, rachises, leaflets, below, and midribs above densely short-pubescent; lenticels ± prominent, small. Petiole and rachis not winged; leaflets in 4-8 pairs, variable in shape, asymmetrical, mostly narrowly ovate to elliptic, acute to long-acuminate, obtuse to rounded at base, puberulent above except on midrib, the terminal pair 7-10 (15) cm long, 2.5-4 (6) cm wide. Spikes axillary or terminal, in groups of 1-4; peduncles 3-4 cm long, densely tomentose; bracts 1 mm long; calyx 3-5 mm long, the lobes acute, ca 0.5 mm long, tomentose; corolla 14-20 mm long, sericeous-villous, the lobes to 1.5 mm long. Legumes flat, 6-20 cm long, 1.5-2.5 cm wide, bearing dense short, ferruginous-tomentose pubescence, the marginal ribs prominent. Foster 703, Shattuck 1122.
Rare; collected along the shore of Gigante Bay and Burrunga Point. Seasonal behavior uncertain. Flowers from January to May. The fruits were mature in the rainy season.
Confused with I. multijuga, which often has nine or ten pairs of leaflets.
Belize to Panama; Trinidad. In Panama, known from tropical moist forest in the Canal Zone and Darien and from tropical wet forest in Colon (Salúd) and Darien.