Slender rhizomatous herb, often reddish tinged, to c. 50 cm high, with erect, usually few-branched stems. Leaves mostly basal, lamina narrowly ovate to obovate, 2–6 cm long, 5–15 mm wide, hastate at base with lobes narrow and usually widely diverging to c. 2 cm long, or the upper stem leaves sometimes entire and linear. Inflorescence a narrow panicle with more or less erect branches, rarely unbranched and spike-like; perianth green to deep reddish-purple; flowers shortly pedicellate; males with segments oblong to elliptic, 1.5–2.5 mm long, the inner 3 broader than outer; female flowers initially c. 0.5–1 mm long, the inner 3 segments rapidly enlarging to c. 1.5 mm long at maturity. Nut ovate, acute, 1–1.5 mm long, smooth and shining but remaining enclosed within the adherent inner perianth segments. Flowers Sep.–Nov.