Rhizomatous perennial, up to 0.9 m high. Flowers: in a cluster of sessile spikelets; whitish with dark brown markings or almost black; glumes 2.8-4.5 mm long; anthers linear, 1.00-1.75 mm long; style 3-cleft; Oct.-Apr. Fruit a 3-sided nutlet, smooth or wrinkled.
Rhizomatous perennial to 30 cm. Spikelets black and straw-coloured.