Plants in the genus rein orchid are mainly terrestrial plants with fleshy tubers and upright, tall, thin or fleshy stems. The leaves are either arranged in a rosette at the base of the plants or scattered up the stem. The flowers are resupinate, usually small, white, green or yellowish and arranged along a tall flowering stem. The dorsal sepal and petals overlap to form a hood over the column. The labellum has a spur and usually three lobes which may be short or long and threadlike. The distinguishing feature of the genus is the presence of two club-shaped projections on the stigma. About 880 species of rein orchid have been formally described. They are native to every continent except Antarctica, growing in both tropical and subtropical zones. Rein orchid are distributed in tropical and subtropical regions. Seventeen species are known in Australia.