Annual herbs up to c. 1 m. tall, monoecious; stems sparsely branching. Stinging hairs few, up to c. 1.5 mm. long, mostly restricted to upper part of the stem. Leaves crowded towards stem apex, 8–12 x 5–7 cm., ovate; apex acuminate; base rounded to truncate; margin finely serrate with 12–15(30) teeth per side; lamina glabrous or puberulent on both sides, with few stinging hairs, lateral nerves 3–6 pairs. Petiole 5–8 cm. long, pilose to glabrescent, stinging hairs occasional. Stipules 3–5 mm. long, linear. Inflorescences usually bisexual, in axils of upper leaves, or in axils of fallen leaves just above soil level, paniculate, but apparently interrupted-spicate due to reduction of side branches, up to c. 30 cm. long, flowers in cymose clusters c. 10 mm. in diam. Male flowers appearing first, pedicels c. 1 mm. long, perianth 1–2 mm. in diam., (3)4-merous, tepals corniculate. Female flowers pedicellate, pedicels c. 0.5 mm. long, unwinged; ovary compressed, stigma sessile 3-branched. Achenes c. 1.75 mm. long, ovoid, laterally compressed, with a circular ridge surrounding a rugose central part, not stipitate, shed without the perianth.
