Robust climber to 20 m. Tubers in dense clusters of 3–5, subtended by a small, globose woody crown, each tuber c. 9–25 by 6–20 cm, annually to perennially replaced, usually clavate or ovate to globose, shallowly buried. Indumentum usually present on all parts, densest on young shoots and inflorescences, hairs simple, 0.4–1.5 mm long. Stems 5.5–9 mm in diam., twining to the left, annual, toward base woody and densely prickly, distal stem with prickles lax or unarmed, terete, young stem sometimes glaucous, mature stem glabrescent. Leaves 3-foliolate, alternate, chartaceous, leaflets with at least three main veins, all of which reach the acute to acuminate apex, margins entire, terminal leaflet blade obovate to broadly so, base acute to cuneate, lateral leaflet blades ovate to broadly ovate, asymmetric, base truncate or obtuse to rounded; petioles 6.5–20(–26) cm long, sometimes prickly; cataphylls, bulbils and lateral nodal organs absent. Inflorescences spicate, pendent, tepals free, inserted on a discoid torus; male inflorescences usually produced before leaves develop fully, compound, 1–2(–3) per axil, partial inflorescences 1 per axil, flowers dense to lax, axis 0.4–2.8 cm long, peduncle 1.9–5.6 mm long; female inflorescences not appearing until leaves are fully developed, simple, 1(–2) per axil. Male flowers with outer tepals 0.4–0.7 by 0.3–0.5 mm, ovate to narrowly obovate, inner tepals 0.5–1.2 by 0.7–1.2 mm, ovate to broadly so; stamens 6. Capsules 40–52 by 22–28 mm. Seeds 6–13 by 6–10 mm, ovoid-lenticular; wings extending from seed bases, 14–25 by 8–12 mm, oblong to ovate-oblong.