A family of monocotyledons (see monocotyledon) that are rush-like, rhizomatous (see rhizome) herbs. They vary considerably in height, from a few centimetres to 2 m. The leaf-blades are rarely developed, although a dry, withered blade may be present, but at each node on the tough, wiry shoots there is a sheathing leaf-base. In some species the leaf-bases are well developed, although not photosynthetic. Ligules are rarely present. The shoots are adapted to become the photosynthetic organs, and are either simple or branched, and in some species are very branched. The stems are circular, semicircular, or almost 4-sided, and sometimes ribbed. Some are solid, others hollow. The flowers are small, regular, and unisexual, and the species are generally dioecious. Flowers are held in spikelets in a panicle. The spikelets are 1- or many-flowered, with a sheathing spathe. Where the perianth is developed there are 3–6 thin, dry, similar segments, held in 2 series. In male flowers there are 3 stamens, often with the rudiments of an ovary. In female flowers the ovary is superior with 1–3 carpels, and 1–3 locules containing a single ovule. The fruits are dry and nut-like, or three-sided capsules. The seeds contain copious endosperm. There are 38 genera and about 400 species, mostly found in S. Africa and Australia, often in very dry habitats, or those which experience heavy seasonal rains. The shoots and roots show adaptations to drought and to waterlogging respectively. Some species are used for thatching and matting.
Subjects: Plant Sciences and Forestry.