Bijdr. (1825) 404
Terrestrial plants, with subterranean tubers. Stem elongated, few- to many-leaved. Leaves sheathing at the base, usually broad and crowded, often spirally arranged, glabrous, persistent, convolute, herbaceous. Inflorescence a terminal, few- to many-flowered raceme. Flowers small, resupinate, usually green, brownish, white, or yellowish. Sepals free. Petals free, usually more or less intermediate in shape between the dorsal sepal and the lateral sepals. Lip spurred, not mobile, 3-lobed, spur short, globose, to elongated, clavate to narrowly tubular. Column-foot absent. Pollinia 2, sectile, caudicles present, stipe absent, viscidium present. Stigma with two widely separated, cushion-shaped lobes, which are adnate to the base of the lip.
Southeast Asia, Indochina, Japan, Malaysia, Indonesia, the Philippines, Papua New Guinea, Australia, Pacific islands, east to Tahiti. About 70 species; in New Guinea about 15 species.
Terrestrial in forests and damp open places in the lowlands as well as in the mountains, including subalpine grassland.
This genus of tuberous terrestrial plants is closely related to Habenaria. It has uniformly insignificant flowers that differ from Habenaria in the structure of the column, in that the stigma-lobes are not on stalked appendages, but on cushion-shaped processes that are adnate to the base of the lip. Many species of Peristylus have a very short, swollen and sac-like spur, which is not found in the habenarias of New Guinea. This genus is rarely seen in cultivation.