Contribution to the taxonomy of Garcinia (Clusiaceae) in Africa, including two new species from Gabon and a key to the Lower Guinean species

Garcinia has some 260 species and is often regarded as a genus with a difficult taxonomy. No recent treatment is available for the botanically rich Lower Guinea phytogeographical region. This study aims at partly filling this gap. First, several taxonomic problems are solved. G. chromocarpa is reduced to a variety of G. quadrifaria. G. gnetoides and G. granulata are both synonyms of G. quadrifaria. G. zenkeri is a synonym of G. densivenia and lectotypes are being designated for both names. G. brevipedicellata is a synonym of G. afzelii, as is G. antidysenterica for which a lectotype is designated. Second, two new species endemic to Gabon are described: Garcinia gabonensis Sosef & Dauby and Garcinia obliqua Sosef & Dauby. Finally, an identification key to all species present in the Lower Guinea region is provided. A few remaining West African species names could not be placed with certainty, because the type material was lost or not traced yet. One is a Rutaceae while the remaining three are provisionally to be regarded as synonyms of G. smeathmannii.