Grass-like herbs (sometimes large) with terete or often triangular stems; leaves linear, parallel-veined; flowers unisexual or perfect, in heads, spikes, spikelets, each flower in the axil of a bract; perianth none or reduced to bristles or scales; stamens 2-3; carpels 2-4; ovary 1-celled, with 1 ovule; stigmas 2-4; fruit a 2-4-sided achene. Sedges.