Pollen morphology and classification of theVernonieae(Compositae)

Abstract

Pollen morphology and chloroplast DNA data are very useful in defining the tribes of the Compositae. Within the tribe Vernonieae, pollen is a good character for delimiting sections, subsections, and series in the genus Vernonia. The prevalence of the unspecialized type A pollen in the genera segregated from Vernonia limits the utility of this character for placing these taxa. Both the pollen and chloroplast DNA data indicate that the tribe needs much research to define its constituent monophyletic groups.