Some Notes on the Gemmiferous Species of Asplenium in Tropical East Africa

Abstract

presence of approximately 420 species, among which are about 75 species of Asplenium. Of the latter, not less than 24 (32%) have been found to regularly or occasionally produce gemman on their fronds. It is interesting to note that nearly the same percentage of gemmiferous species occurs in other parts of tropical Africa: Flora of West Tropical Africa area, 16 of 49 (33%) species gemmiferous (Alston, 1959); Madagascar and the Comoro Islands, 19 of 58 (33%) species gemmiferous (Tardieu-Blot, 1958); Flora Zambesiaca area, 13 of 41 (32%) species gemmiferous (Schelpe, 1970). The gemmiferous species of Asplenium in East Africa can be divided into five groups on the basis of the position of the gemmae on the fronds. The groups are not intended to be natural, but they often do contain taxonomically closely related species. The possible relationships among the species in each group are discussed in the account of the group.