Herbs, mostly perennial, tufted or with erect or creeping rootstock. Leaves mostly basal, cauline, few or absent, distant, flat or cylindrical, linear or filiform, sheathing at base, sometimes reduced to sheaths only; sheaths open or closed, often ± auricled. Inflorescence cymose, bracteate, often panicled, corymbose or capitate. Flowers small, usually actinomorphic, bisexual, bracteate. Perianth segments (tepals) 6, (rarely 3), biseriate, free glumaceous or coriaceous, rarely white, mostly lanceolate, equal to unequal. Stamens (3-) 6, opposite the perianth segments; filaments thin, usually longer than anthers; anthers dithecous, longitudinally introrse; pollen in tetrads. Ovary 3-carpellary, syncarpous, superior, 1 (-3)-celled; stigmas 3, papillose, on short or long style, usually not exceeding the flower; placentae basal or 3, parietal, 3-manyovuled. Capsules often ± triangular, ovate, elliptic to lanceolate, shorter to much exceeding the perianth, 3-valved, loculicidal; seeds very small, sometimes tailed; embryo small, usually straight and in the middle of the endosperm.