Deciduous trees, to 10 m high, branchlets terete, 2-25 cm thick, with prominent leafscars. Leaves simple, alternate spiral, clustered; latex milky, estipulate; lamina 20-50 x 8-12 cm, obovate-spathulate, oblong, oblanceolate; base cuneate, apex obtuse or acute, margin entire, glabrous, subcoriaceous; lateral nerves to 25-45 pairs, parallel, prominent, intercostae scalariform; petiole 3-8 cm long, stout, glabrous. Flowers bisexual, white, in terminal corymbose stout cymes; calyx cupular, 5 mm; lobes 5, subequal, round, obtuse; corolla 6 cm across; tube 4 cm, expanded from above the middle; lobes 5, obovate, overlapping to the left, obtuse; stamens 5, attached at the base of the tube, included; ovary half inferior, globose, ovules many; stigma 2-lobed, subsessile. Fruit an aggregate of 2 follicle, pustulate; seeds winged.