A new generic classification for African peucedanoid species (Apiaceae)

Abstract

The African species currently residing in Peucedanum L. and associated platyspermous genera are not related to the Eurasian Peucedanum species. As the type of the genus is P. officinale L., which is part of the Eurasian group, a new generic classification is proposed for the African group. The affinities and circumscriptions of two previously enigmatic monotypic genera, Afroligusticum C. Norman and Erythroselinum Chiov., are clarified. The former is expanded, while the latter is subsumed into Lefebvrea A. Rich. along with six Peucedanum species. New combinations are formalized for 49 of the 58 species recognised, which are accommodated in six genera, as follows: Afroligusticum (13 spp.), Afrosciadium P.J.D. Winter gen. nov. (18 spp.), Cynorhiza Eckl. & Zeyh. (3 spp.), Lefebvrea (10 spp.), Nanobubon A.R. Magee gen. nov. (2 spp.), and Notobubon B.-E. van Wyk gen. nov. (12 spp.). Ten new synonyms are presented, in Cynorhiza (2), Lefebvrea (6) and Notobubon (2). Diagnostic characters include habit (woody shrubs, perennial herbs or monocarpic herbs), seasonality (evergreen or deciduous), leaf texture and arrangement, inflorescence structure, fruit morphology (size, shape and wing configuration) and fruit anatomy. The results of maximum parsimony analysis of 125 nuclear rDNA ITS sequences representing all tribes and major clades of the apioid superclade and closely related outgroups support the separation of the African group of genera from that of Eurasian Peucedanum.