Perennial, forming clumps from a ± bulbous base; culms 5-80 cm high, geniculately ascending. Leaf-blades 2-20 cm long, 2-7 mm wide. Panicle 2-12 cm long; involucres cup-shaped, 3-7 mm long; inner spines short, flattened, connate for a quarter to half their length to form a cup, glabrous or obscurely puberulous and grooved on the face, occasionally sparsely ciliate on the margins, green to dark purple, antrorsely scaberulous, narrowly triangular at the tip; outer spines few, short, often suppressed, rarely almost as long as the inner. Spikelets 1-3 per burr, 3-5 mm long.