Description from Flora of China
Herbs, annual, without chlorophyll, mycotrophic, rhizomatous. Stems simple or branched. Leaves cauline, bractlike, small. Inflorescences terminal, racemes or flower solitary. Perianth tube actinomorphic, salverform, lateral wings absent, without annulus at mouth; tepals 6, apically distinct; outer tepals larger than inner, slightly 3-lobed; inner tepals very small. Stamens 3, sessile on perianth tube; connectives generally not appendaged. Ovary ovoid to globose, 1-loculed, with 3 parietal placentae; placentae each with a large globose gland at both sides of apex; stigmas 3, often appendiculate. Fruit capsular, perianth caducous but perianth base persistent; dehiscence generally irregular or by longitudinal slits.
About 26 species: Africa, tropical America, Asia, New Guinea; one species in China.