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Abstract
Altogether 100 specimens of 16 species of this highly diversified genus have been studied. Pollen morphology has been found useful in the grouping of the species, but of no use for distinguishing between species within the same group. The three earlier established pollen-types, the Crassiuscula-, Kilimandscharica- and Volkensii-types, have been confirmed. The inter- and intraspecific variation in the Crassiuscula-type, is mainly in sexine thickness, shape of bacula and processes. In the other two types, the variation is mainly in sexine pattern, shape and width of lirae. The three pollen-types are illustrated with scanning electron micrographs (SEMG) and transmission electron micrographs (TEMG).