A spindly scandent, or straggly lax-branched shrub or small tree up to 12 m high, rarely taller, usually dioecious.Bark grey, ± smooth.Young shoots and petioles patent-hirsute (forma hirtella) or appressed-puberulous (forma glabrata).Stipules 3–5 mm long, setaceous.Petioles 0.3–2 cm long, often geniculate.Leaf blades 5–20 × 2–8 cm, elliptic-oblanceolate, shortly acuminate at the apex, attenuate to a cuneate or cordulate base, remotely glandular-crenate on the margins, penninerved, with a pair of glands on leaf upper surface towards the base, glabrous above, puberulous and later glabrescent beneath (forma glabrata) or with the midrib sparingly setose beneath (forma hirtella), dark green and shiny above, paler beneath; the lateral nerves in 6–14 pairs, bearing domatia on leaf lower surface.Male inflorescences up to 30 cm long, usually terminal, less often axillary or borne on old wood, broadly paniculate.Male flowers ± sessile; buds 0.5 mm long, subglobose, orange; sepals 2, cupular, reflexed, reddish; stamens 8, the united filaments forming a basal plate.Female inflorescences not usually more than 10 cm long, terminal, rarely cauliflorous, spicate, few-flowered, lax; bracts 2 mm long, biglandular at the base.Female flowers subsessile; sepals 5, 1.3 mm long, lanceolate, acute, minutely denticulate; ovary 1 × 1.5 mm, 3(4)-lobed, smooth or ± so, evenly appressed-pubescent; styles commonly up to 2 cm long, rarely longer, united at the base, linear-filiform, minutely papillose, reddish.Fruits 5 × 9 mm, 3-lobed, smooth or ± so, sparingly minutely puberulous, green.Seeds 4.5 × 4 mm, ovoid-subglobose, smooth, shiny, light brown, faintly-mottled.