Herbs, annual, 3.5–7 dm, monoecious. Stems erect, pubescent, sparsely hirsute, and stipitate-glandular. Leaves: petiole 1.5–6.5 cm; blade ovate, 3–8 × 1.5–5 cm, base cordate, margins serrate, apex acute to short acuminate. Inflorescences unisexual, axillary (staminate) and terminal (pistillate; sometimes on short lateral branches, appearing axillary); staminate peduncle 0.5–1.5 cm, fertile portion 0.5–3.5 cm; pistillate peduncle 0.1–1 cm, fertile portion 3–7 × 0.7–1 cm; allomorphic pistillate flowers common, near apices of pistillate inflorescences. Pistillate bracts (normal and allomorphic flowers) loosely arranged (inflorescence axis visible between bracts), 3–6 × 6–8 mm, abaxial surface pubescent (hairs to 0.3 mm) and sparsely stipitate-glandular; lobes (9–)13–17, linear, 2/3 bract length, muricate. Pedicels of allomorphic flowers rudimentary. Pistillate flowers: pistil 3-carpellate (normal flowers), 1(–3)-carpellate (allomorphic flowers); styles multifid or laciniate. Capsules spiny, pubescent; allomorphic fruits obovoid, 2 irregular flanges near apex, 2–2.2 × 1.6–1.8 mm, smooth, pubescent. Seeds 1.6–2 mm, tuberculate.