Galdieria partita

Galdieria partita is a species of extremophilic red algae that lives in acidic hot springs. It is the only unicellular species of red algae known to reproduce sexually. It was discovered in 1894 by Josephine Elizabeth Tilden from Yellowstone National Park in the western United States. Originally described as a species of green algae, Chroococcus varium, its scientific name and taxonomic position were revised several times. In 1959, Mary Belle Allen produced the pure culture which has been distributed as the "Allen strain".