Pollen morphological studies of some members of family <i>Sapindaceae</i>in Nigeria and their taxonomic significance

Pollen morphology of 21 species of Sapindaceae was examined using light microscopy with a view to providing additional characters that could help in identification, as well as show the relationship among the species. Pollen samples were subjected to standard acetolysis method. Quantitative and qualitative pollen morphological characters were carefully studied and data were subjected to cluster analysis so as to show the similarities among the species. The pollen grains of the species were 3-aperturate, small to medium-sized and endoapertures were rounded, lo-longate or la-longate. The exine pattern was mostly psilate while striate and reticulate were observed in Lychnodiscus reticulatus and Cardiospermum species, respectively. The apertures were mostly colporate and porate but rarely syncolporate and parasyncolporate as observed in Eriocoelum macrocarpum and Lychnodiscus reticulatus, respectively. A wide variation was observed in the quantitative pollen characters. The largest pollen size (33.90 × 50.70 μm) was observed in Cardiospermum halicacabum and the smallest (8.55 × 19.25 μm) in Allophylus africanus. The cluster analyses separated the taxa into two major groups based on aperture type, pollen shape, endoaperture type and pollen length. The pollen characters studied showed the relationship among the species and can be utilised in distinguishing the species of this family.