Herbs. Stems annual, immature erect, older climbing, 1-2 m, occasionally branching, herbaceous, glabrous; prickles absent. Leaves numerous, evenly distributed; tendrils numerous, long, functional; blade deltate-ovate, pandurate, or cordate-ovate, the larger hastate, thin, 5-12 × 2-5 cm, coriaceous, glabrous, glaucous abaxially, base truncate to subcordate; apex round to cuspidate. Umbels solitary or in sets of 3, axillary to leaves, 10-35-flowered, loose, subglobose; peduncle shorter than to 1.5 as long as subtending leaf. Flowers: perianth greenish; tepals 1.5-2.5 mm; anthers equaling or slightly larger than filaments; ovules (1-)2 per locule; pedicel 0.3-1.5 cm. Berries blue to black, subglobose, 4-6 mm, glaucous. 2n = 30. Flowering May--Jul. Bogs, wet woods, marshes, pocosins; Del., D.C., Ga., Md., N.J., N.Y., N.C., Pa., S.C., Va.