Large tree to over 20 m high, with broad spreading crown. Shoots glabrous, stout, dark, with prominent, Y-shaped lf scars; buds grey, ± finely puberulent. Lvs to c. 55 cm long; petiole and rachis to c. 30 cm long on adult branches. Leaflets 5-9, densely glandular-puberulent when young, becoming glabrous except for axillary hair tufts on undersurface, entire; base cuneate to rounded; apex rounded to acute or cuspidate; lowest pair of leaflets much smaller; terminal leaflet largest. Lamina of terminal leaflet mostly 10-20 × 5-11 cm (sometimes larger on strong vegetative shoots), broad-elliptic or elliptic-obovate. ♂ catkins 5-11 cm long, puberulent. ♀ fls in clusters of 1-3, sessile or subsessile, densely glandular-puberulent; stigmas to 3 mm long, pale green. Fr. 3.5-5 cm long, subglobose, glabrous but gland-dotted, green, not beaked. Shell thick or thin, rugose; sutures thick and easily dividing in 1/2 at maturity. Seed very convoluted.