XVI International Botanical Congess

The embriologic characters have been barely utilized in plant systematics, even though they have showed to be important for the delimitation of taxa at different levels of the classification. Furthermore, the quantitative analysis of such characters remains unexplored, despite its high potential for Taxonomy. This study compares 18 species of cacti by means of phenetic techniques. A total of 15 quantitative characters of mature ovules and seeds were used for this purpose. The groupings obtained from the analysis are consistent with the classification of the Cactaceae in three subfamilies, which is based mostly in macromorphological characters. The taxonomic significance of the embriologic characters at the infra-subfamilial level is suggested by the tendency of the species within a same genus to cluster together.