Pollen morphology and biometry in Androcymbium (Colchicaceae)
The pollen of 34 individuals representing the 10 species and subspecies of the section Erythrostictus (Schlecht.) Bentham and 3 species of the section Cymbanthes Bentham in the genus Androcymbium Willdenow was examined with scanning electron microscopy to investigate the degree of morphologic differentiation within and between these two sections of the genus. Diporate pollen morphology was observed for all these taxa except for Androcymbium capense (L.) Krause (section Cymbanthes), which was triporate. Given the specific importance traditionally given to this character, some doubt is cast upon the naturalness of this section. Surface sculpturing was reticulate in both sections for all of the analysed species except for Androcymbium psammophilum Sventenius (section Erythrostictus), which was rugulate-perforated. A canonical analysis of populations based upon four pollen biometrie parameters measured on the analysed individuals belonging to section Erythrostictus was run. The pattern of groups displayed by the corresponding canonical representation furnishes other evidence that supports the establishment of more accurate taxonomic relationships among the species that are presently included in the complex Androcymbium gramineum (Cav.) McBride. Key words: Colchicaceae, Androcymbium, pollen, biometry, taxonomy, canonical analysis.