Perennials of small to moderate size, 10-130 cm. Rhizome short caespitose to long creeping. Stem scapose or noded, usually arising intravaginally in centre of leaf rosette; in some species extravaginally. Leaves concentrated at basal parts of stem, lowest often present as blade-less sheaths; one side of sheaths scarious, other thicker and with sturdy nerves; sheaths and stem bases of previous seasons sometimes forming conspicuous tussocks; ligule scarious, straight or arched. Inflorescence single spike (actually spike-like structure), multiple spike or paniculodium of several bisexual or unisexual spikes; branches with basal tubular prophyll, absent in subg. Vignea. Partial inflorescences subtended by sheathing or sheath-less bracts of variable size, from small glume-like to wide, foliose and overtopping the inflorescence. Male flowers mostly with three stamens and supporting male glume, forming true spikes. Female flower is surrounded by closed prophyll, termed utricle or perigynium, occasionally accompanied by reduced inflorescential branch, rachilla; style base occasionally expanded, rarely articulated; stigmas 2 or 3. Fruit biconvex or triangular nutlet, as a rule reticulate with papilla in each areole.

A genus with c. 1000 cosmopolitan species, distributed especially in temperate and cold wet regions; represented in Pakistan by about 62 species.