Résumé
The paucity of distributional data on Orchidaceae Juss. of Central Atlantic Africa along with the severity of threats to humid forests in Africa and to their epiphytes, led us in 1997 to undertake an intensive sampling campaign in this region. Analysis of the new specimens generated and examination of historical collections have resulted in a number of taxonomic advances regarding several endemic species of Atlantic Central Africa, or previously considered as endemic, and have resulted in updates of their known ranges. The following taxonomic changes are made: Ancistrorhynchus constrictus Szlach. & Olszewski is placed in synonymy under Ancistrorhynchus capitatus (Lindl.) Summerh.; Bulbophyllum mayombeense Garay is placed in synonymy under Bulbophyllum schinzianum Kraenzl. var. schinzianum; and B. kupense P.J.Cribb & B.J.Pollard is placed in synonymy under B. teretifolium Schltr., for which a neotype is designated. The geographical distribution of several taxa is amended: Aerangis megaphylla Summerh. is shown to be endemic to the island of Annobon; Polystachya superposita Rchb.f. is recognized as endemic to Cameroon, and Liparis suborbicularis Summerh. is known only from Nigeria and Cameroon. Three new records are indicated: Aerangis bouarensis Chiron for Cameroon, Bulbophyllum schinzianum Kraenzl. var. schinzianum for the Republic of Congo, and Liparis goodyeroides Schltr. for Liberia. Conservation assessments based on IUCN categories and criteria are provided for each taxon.