Phylogenetic Relationships and Evolutionary Aspects

Abstract

If one looks at any particular species of μm, one will not experience any problem or uncertainty in recognizing it as a member of the genus. The sexually dimorphic, anemophilous flowers with their hairy, long stigmas and the large anthers dangling on long, thin filaments and the dry, dehiscent fruits with their characteristic anatomy “hold” the genus together. And yet, there is extreme variability within the genus in growth form (large shrubs … perennial herbs, etc.), corolla tube lengths and shapes (long and ± cylindrical … short and subcampanulate), in the sex distributions (non-dioecious, dioecious) and several other features.