Taxonomy and Natural History of Hydnora (Hydnoraceae)

Hydnora is a genus of subterranean holoparasitic herbs found in arid and semiarid regions of Africa, Madagascar, and the southwestern part of the Arabian peninsula. Results from field and herbarium studies suggest the genus consists of four or five species, although more than 12 have been described. The recent rediscovery of H. triceps, a plant that had remained uncollected for a century, supports the need for additional field work. Taxonomic research has been impeded by a paucity of collections, which are often fragmentary in nature and poorly preserved. Supraspecific classification, species complexes, floral biology, and uses are discussed