A monoecious or dioecious, 1-1.5 (-3) m tall, shrub with 4-angled, glabrescent twigs. Leaves mostly opposite, with 2.5-20 cm long petiole; lamina 3-costate, broadly ovate to orbiculate, 6-22 cm long, 5-15 cm broad, sparsely appressed hairy, scabrous, dentate, somewhat cuneate, truncate or subcordate at the base, acuminate; stipules triangular-lanceolate, 8-12 mm long. Cymose clusters of flowers arranged on axillary, drooping, up to 30 cm long spikes. Flowers white, tetramerous; bracts lanceolate, 3-4 mm long. Sepals c. 1 mm long, pubescent, acute. Stamens exserted. Style long exserted. Achenes pale brown, c.l mm long, beaked, glossy.