Five new species of Streptocarpus (Gesneriaceae) from Katanga, D.R. Congo

Background and aims - Five new species of Streptocarpus (Gesneriaceae) are described from D. R. Congo in connection with preparing the family treatment for the Flore d'Afrique centrale. Methods - Standard herbarium practices were applied. Key results - Streptocarpus malachiticola sp. nov. is related to S. compressus and S. goetzei while S. bampsii sp. nov., S. malaissei sp. nov., S. salesianorum sp. nov., and S. schaijesii sp. nov. are related to S. michelmorei and S. solenanthus. The differences with these species are discussed and distribution maps for the new taxa are presented. An identification key for all known acaulescent species from D.R. Congo, Rwanda, and Burundi is provided. The conservation status of new species is preliminarily assessed. All taxa are range-restricted in Upper Katanga and the assessments are as follows: S. malachiticola: EN B1+2ab(iii), S. bampsii: CR B2ab(iii), S. malaissei: EN B1+2ab(iii), S. salesianorum: CR B2ab(iii), and S. schaijesii: EN B2ab(iii). Streptocarpus malachiticola is found on metalliferous rocks while the remaining species are either epiphytes in gallery forests (S. bampsii) or occur on humid rocks in gallery forests.