Within the Gentian family, four genera contain mycoheterotrophic species. Voyria has more than a dozen species, the other genera Voyriella, Exacum, and Exochaenium contain only a few mycoheterotrophic species. Some green gentians are potentially partially mycoheterotrophic (Obolaria, Bartonia).


Classification: Eudicots, Gentianales

Genera with mycoheterotrophic species: Voyria, Voyriella, Exacum, Exochaenium

Diversity: Gentianaceae comprise 92 commonly accepted genera and over 1,650 species. Twenty-five species are achlorophyllous and putative full mycoheterotrophs. These species are part of four genera: Voyria, Voyriella, Exacum, and Exochaenium. Species of the North American genera Bartonia (four spp.) and Obolaria (one sp.) are partial mycoheterotrophs. Partial mycoheterotrophy is suggested to occur in Curtia tenuifolia and species of Neurotheca as well.

Distribution and habitat: Gentianaceae are a cosmopolitan family, absent only from Antarctica. The majority of the species occurs in temperate  zones but the mycoheterotrophic species are restricted to rain forests in the Americas (Voyria, Voyriella), West Africa (Voyria, Exochaenium), and Southeast Asia (Exacum). Apart from tropical forests some species of Voyria also occur in savannas and extend into subtropical Central America.