Vines. Stems annual, climbing, branching, to 2.5 m, herbaceous, glabrous; prickles absent. Leaves: petiole thin, 1–6 cm; tendrils numerous, long, functional; blade oblong-ovate, ovate, or round, 4.5–12 × 3–9 cm, glabrous abaxially, base cordate to truncate, margins entire, apex obtuse to acute; proximal cauline leaves narrower and smaller. Umbels many, axillary to leaves, 20–100+-flowered, globose; peduncle to 30 cm, progressively shorter distally. Flowers: perianth greenish, carrion-scented; tepals 3.5–4.5 mm; anthers much shorter than filaments; ovules (1–)2 per locule; pedicel 0.5–2 cm. Berries blue, subglobose, ca. 10 mm diam., glaucous. 2n = 26.