Phylogeny and evolution of Perezia （Asteraceae： Mutisieae： Nassauviinae）

A molecular phylogenetic analysis of most of the species of Perezia reveals that, as traditionally defined, the genus is not monophyletic with two species more closely related to Nassauvia than to Perezia. In addition, our results show that Burkartia （Perezia） lanigera is related to Acourtia and is the only member of that clade in South America. The remaining species are monophyletic and show a pattern of an early split between a western temperate and an eastern subtropical clade of species. Within the western clade, the phylogeny indicates a pattern of diversification that proceeded from southern, comparatively low-elevation habitats to southern high-elevation habitats, and ultimately into more northern high-elevation habitats. The most derived clades are found in the high central Andes, where significant radiation has occurred.     

Six new species ofAcourtia (Asteraceae) and a historical account ofAcourtia mexicana

Six Mexican species ofAcourtia are described. One of these novelties seems to be related toAcourtia mexicana (Lag. ex D. Don) H. Rob., whose nomenclature has been misunderstood for decades; an exhaustive literature review and examination of herbarium material supports Robinson’s combination.

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Resumen  Se describen seis nuevas especies mexicanas deAcourtia. Una de estas novedades parece estar relacionada conAcourtia mexicana (Lag. ex D. Don) H. Robinson, especie cuya nomenclatura ha sido mal interpretada por décadas; una exhaustiva revisión de la literatura así como de material de herbario, apoyan la combinación de Robinson.