Erect or ascending perennial 20–80 cm high, glabrous, woody at base; stems simple or branched from base, each with 3–5 terminal fertile branches which are further branched. Cauline leaves sessile, alternate, linear-lanceolate, 10–40 mm long, 2–8 mm wide, apex acute to obtuse, mucronate, base cuneate, margins entire or finely serrulate; leaves on fertile branches ovate to triangular, to 55 mm long, 30 mm wide. Cyathia 1 or 2 in uppermost axils or 2 or 3 terminally; peduncles to c. 1 mm long; involucre campanulate, c. 2 mm long; glands lunate to reniform, to c. 1.5 mm long, entire to slightly undulate, with 2 slender white horn-like appendages; female flowers with styles divided to the middle into 2 filiform stigmas. Capsule depressed-globose, 3–5 mm long, 4–5 mm wide, pendulous, keeled, smooth; seeds more or less globose, c. 2.5 mm diam., smooth, grey, sometimes dark-mottled, caruncle peltate, ovoid, keeled, white. Flowers Jul.–Oct.