Taxonomy and conservation of the genus Psychotria (Rubiaceae) in S.Tomé e Príncipe (Gulf of Guinea)

A revision of the species of Psychotria from S.Tome e Principe is presented, including a key to the species, full descriptions, distribution, conservation status, notes and specimens examined. Twelve species occur on the islands of S.Tome and Principe; seven are endemic, six to S.Tome and one to Principe. One new species (P. exellii sp. nov.) is described from S.Tome. The conservation status of five endemic species is evaluated using IUCN guidelines/criteria and categories of threat are proposed. Two IUCN Red List endemics (P. guerkeana and P. grumilea) are re-evaluated and a different category of threat is proposed for P. grumilea. Three of the seven endemic species are considered Critically Endangered, one Endangered and three are Vulnerable, using the criteria for extinction threat set by the IUCN. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2004, 147, 469–481.