Cordyceps is a genus of ascomycete fungi (sac fungi) that includes about 400 species. All Cordyceps species are endoparasitoids, parasitic mainly on insects and other arthropods (they are thus entomopathogenic fungi); a few are parasitic on other fungi. Until recently, the best known species of the genus was Cordyceps sinensis, first recorded as yartsa gunbu in Nyamnyi Dorje's 15th century Tibetan text An ocean of Aphrodisiacal Qualities. and known as yarsha gumba in Nepali and ""summer-grass, winter-worm" in English. In 2007, nuclear DNA sampling revealed this species to be unrelated to most of the rest of the genus' members; as a result it was renamed Ophiocordyceps sinensis and placed in a new family, the Ophiocordycipitaceae.