Erect, monoecious annual, sparingly branched, farinose at least when young, sometimes brownish purple or reddish purple. Stems to 2.5 m high, much less in impoverished soil, stout, angular. Lvs below infl. (excluding those at base of plant) with petioles to 5 cm long; lamina 5-30 × 3-20 cm, triangular-hastate, ovate, or sagittate-ovate, narrower in infl., irregularly dentate, sinuate, to almost entire; base deeply or shallowly cordate to truncate; apex rounded to acute. Infl. terminal, narrow-paniculate, to 40 cm long; branches slender. ♂ fls: perianth c. 0.5 mm long, green with hyaline margin. ♀ fls: dimorphic, most with 2 bracteoles and perianth 0, otherwise with 5-lobed perianth and bracteoles 0. Bracteoles free, orbicular or suborbicular, very shortly stalked, entire, without appendages or tubercles, strongly accrescent, 6-12-(15) mm diam. at fruiting. Fr. circular to broad-elliptic, flattened, dimorphic: in perianth fls 1.5-2.5 mm diam. and horizontal, in bracteolate fls 2.5-4.3 mm diam. and vertical; pericarp removed fairly easily. Testa shining black, almost smooth.