Epiphytic or rarely epilithic herbs, sympodial, with short rhizomes. Stems not thickened into pseudobulbs, tufted, slender, compressed, erect, sheathed. Leaves apical, solitary, leathery to fleshy, stalkless or stalked. Inflorescences terminal racemes, usually shorter than leaves, erect or arching. Flowers resupinate, usually solitary, small to medium sized, variously coloured. Sepals dissimilar, dorsal free, erect, narrow, often clubbed at tip, laterals almost entirely fused and concave at base. Petals similar to dorsal sepal but smaller. Labellum small, entire or 3-lobed, side lobes erect with short filamentous points, midlobe strap-like, rounded or notched at tip. Column long, slender, arching, with a short foot. Pollinia 4, waxy.
About 30 species from tropical and sub tropical N, C and S America.
Flowers dominated by the joined lateral sepals; dorsal sepal and petals narrow and clubbed at tip; small tufted plants lacking pseudobulbs.
Source: (2005). Orchidaceae. In: . Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.