Monoecious, twining perennial to 2.5 m, with stinging hairs. Leaves cordate to sagittate, slightly toothed, paler beneath. Flowers in slender, axillary, bisexual spikes, greenish, females basal.
Twining, pubescent herb. Leaves alternate, ovate, cordate at base. Racemes terminal or leaf-opposed, with numerous male flowers above and 1 or 2 basal female flowers. Flowers greenish yellow.