Perennial with erect stems to c. 1 m high. Basal leaves usually with petioles longer than lamina; lamina oblong-ovate, 12–30 cm long, 6–15 cm wide, cordate at base; margins plane or undulate; upper leaves reduced, relatively narrower than basal ones, and with non-cordate bases. Inflorescence often c. half the height of the plant, branches more or less erect, usually simple and subtended by a leaf; flower 'whorls' mostly separated by c. 1–10 cm, the lower ones usually subtended by a small leaf. Fruiting valves ovate, trullate, triangular or nearly oblong, 3.5–7 mm long, 2–3 mm wide (excluding teeth), reticulate, 1–3-toothed near base (rarely almost entire), usually only 1 valve developing a rounded callosity up to c. one-third as long as valve; fruiting pedicel c. 1.5–3 times as long as valves, jointed in the lower third. Nut 2.5–3.5 mm long.  Flowers mainly Dec.–Mar.