Shrub or small tree, to 5 m tall. Leaves simple; petioles quite variable in length, very short or to 20 cm long (variable even on the same branch), pulvinate at both ends; blades oblong-lanceolate to oblong-oblanceolate, mostly acuminate, acute to obtuse at base, 4.5-22 cm long and 1.8-9 cm wide (variable in size even on the same branch); midrib raised above. Flowers in short racemes of few flowers in the upper leaf axils; pedicels 1-3 cm long (2-4 cm long in fruit); sepals 4, bluntly triangular, ca 1.5 mm long, open in bud, each with a minute disk gland at base within; petals 4, ovate, ca 1 cm long, obtuse at apex, white; stamens ca 100, 1.5 cm long; pistil oblong, ca 3 mm long, on a gynophore ca 1 cm long (ca 3 cm long in fruit). Fruits oblong, fleshy, tardily dehiscent siliques to 9 cm long, becoming maroon when mature, ca 1.5 cm wide, dehiscing irregularly lengthwise to expose seeds, the seeds ca 20, sticky, +/- spherical, ca 8 mm diam. Croat 5861, 7802. The species is distinguished by a combination of many-staminate flowers, petioles of greatly differing lengths, and purple siliques borne on a gynophore.