Tree, to ca 27 m tall, ca 30 cm dbh; outer bark with many shallow fissures; inner bark smooth, light-colored, the sap with a faint, sweet aroma; young stems puberulent, soon almost glabrous, lenticellate. Leaves alternate, imparipinnate, 25-40 cm long; stipules narrowly deltoid, ca 1.5 mm long; petioles 5-11 cm long; petioles, rachises, and petiolules puberulent; petiolules 4-5 mm long; leaflets 11-15, alternate to opposite, narrowly ovate to oblong-elliptic, bluntly acuminate at apex and downturned, rounded to truncate at base, (3)5.5-11 cm long, (2.5)3-5.5 cm wide, glabrous or weakly appressed-pubescent on midrib of lower surface, drying subcoriaceous, the margins somewhat thickened and turned down; major veins in 6-10 pairs, anastomosing and somewhat loop-connected 5-10 mm from the margin, the reticulate veins prominulous on dried specimens. Inflorescences terminal; flowers not seen. Fruits samaroid, ca 8.5 cm long, 1-seeded, yellowish-green, glabrous except sparsely appressed-pubescent on ventral margin of seminiferous area, the seminiferous area ca 3 cm long, oval, bearing a conspicuous, almost medial ridge, this ridge continuous with the dorsal margin of the wing; wing obovate, mucronate at apex, thin, ca 5.5 cm long, the dorsal margin thickened. Croat 16624, Folsom 3509, Foster s.n.