I. gracilipes Standl. Tree, to 10 m tall; young branches and inflorescences puberulent, otherwise glabrous. Petioles unwinged or winged near apex; rachis winged; leaflets in 2 or 3 pairs, elliptic to oblong-elliptic, acuminate, obtuse to rounded at base, the terminal pair 11-17 cm long, 4-6.5 cm wide. Racemes umbelliform, axillary and solitary (appearing paniculate on new growth); peduncles 2-4 (5) cm long; rachis very short, 3-4 mm long; bracts subulate, ca 4 mm long; flowers long-pedicellate; pedicels slender, 8-12 (15) mm long; calyx 3-5 mm long, the lobes acute, ca 0.5 mm long; corolla 9-14 (17) mm long, the lobes acute, to ca 2 mm long; stamens and style to ca 20 mm long. Legumes flat, 6-18 cm long, l.5-3.5 cm wide, straight or curved, glabrate in age, the marginal ribs prominent. Croat 7877, 11889. Common, at least on the shore. Flowers from August to May, possibly twice a year. Fruit maturity period uncertain; mature fruits have been seen in the early rainy season.