Cladistic and biogeographic analyses of the genera Moscharia and Polyachyrus (Asteraceae, Mutisieae)

The genera Moscharia (two species) and Polyachyrus (seven species) form a m onophyletic group within tribe Mutisieae, subtribe Nassauviinae, defined by the leaves with auricles at their bases, and the capitula with I-seriate i nvolucre. A cladistic analysis of the species of the two genera was carried out using 22 characters from life cycle external morphology, pollen and tr ichomes. Polarity of the characters was based on the outgroup comparison me thod. One cladogram was produced, with 37 steps, a consistency index of 0.7 3, and a retention index of 0.75. The cladogram defines six monophyletic gr oups: (((Polyachyrus annus, (P. carduoides, (P. cinereus, (P. fuscus, P. ga yi))), P. sphaerocephalus), P. poeppigii), (Moscharia solbrigii, M. pinnati fida)). The probable ancestral geographic area for the group, determined by Bremer's method, is North- Central Chile area (30 degrees-35 degrees south latitude). The study suggests that the Pleistocene could be the period of evolution of the ancestor of Moscharia and Polyachyrus.