Perennials, more rarely annuals. Leaves linear, basal or also cauline, flat or canaliculate; Inflorescence capitate, spike-like, or paniculate (in the last case consisting of a terminal and some axillary corymbiform anthelas). Flowers bisexual, or lowest flower bisexual, fertile, the upper ones ♂ or sterile, or lowest flowers ♀, upper one(s) ♂. Stamens (1-)2-3;
Arctic regions absent, Asia-Tropical: New Guinea present; Philippines (Philippines present), E. Java present, Japan present, New World present, Old World present, SE. Asia present, SE. United States of America present, Southern America, W. Malesia present, tropical Australia present present, tropical Central and South America present, tropics and subtropics of the whole world present
Large genus of more than 200 spp., only a few of them widely distributed. In the Old World the genus is but sparingly represented, and it is absent in the arctic regions. Its full development is reached in the New World, especially in the SE. United States of America, the West Indies, and in tropical Central and South America. Of the 12 Malesian spp. R. corymbosa and R. rugosa inhabit the tropics and subtropics of the whole world. Also R. triflora and R. gracillima are widely distributed, but in Malesia they are only known from a few localities. R. rubra, R. longisetis, and R. submarginata extend from SE. Asia to tropical Australia, R. malasica from Japan southward to W. Malesia. In Malesia the SE. Asiatic R. hookeri and R. wightiana were only collected in one or two localities. Two spp. extend from tropical Australia to Malesia, viz R. heterochaeta to E. Java and the Philippines, R. subtenuifolia to New Guinea.
In the list of Nomina generica conservanda et rejicienda the name Rhynchospora is conserved against “Triodon L. C. RICH. in Pers., Syn. 1: 60 col. 1. 1805 pro syn.”. This conservation seems superfluous.