Pantoporate pollen in the Asteraceae (Vernonieae)

摘要

Pantoporate pollen, which occurs sporadically in the Monocots and Dicots, has now been found in Asteraceae in two apparently related genera of the tribe Vernonieae, Polydora Fenzl and Oocephala H.Rob. Disposition of pores in Polydora seems more asymmetric than in Oocephala. Based on the known relationships within the Vernonieae, some conjectures are made regarding development of the pantoporate condition in the group.