Orchidaceae du district phytogéographique du Haut-Katanga (Zaïre): biodiversité et endémisme

Abstract

Starting from the information gathered in the revision of the Orchidaceae for the Flore d’Afrique centrale (Geerinck 1984, Geerinck et al. 1992) as well as from the recent paper dealing with the Orchids of Burundi (Arbonnier & Geerinck 1994), the present contribution firstly discusses diversity both at specific and infraspecific levels for the Upper Katanga district of Zaire. Amongst the 587 taxa of the Flore d’Afrique centrale, some 313 were recognized as present in Upper Katanga (53%), of which 121 present a distribution restricted to the Zambezian phytogeographical regional centre of endemism. Six main patterns of distribution are recognized, some with very restricted area. Two examples of speciation are analyzed, namely for the genus Kryptostoma (Summerh.) Geerinck and for the section Multipartitae Kraenzlin of the genus Habenaria Willd.