Three intercontinental disjunctions in Papaveraceae subfamily Chelidonioideae: evidence from chloroplast DNA

Abstract

An RFLP analysis of the chloroplast genome of Papaveraceae subfam. Chelidonioideae resulted in one most parsimonious tree consisting of three monophyletic groups. Each group contains intercontinental disjunct taxa. Whereas Eomecon/Sanguinaria and Stylophorum are examples for the well known E Asian - eastern N American disjunction, the E Asian -C and S American disjunction in Macleaya/Bocconia is rare. The genus Stylophorum in this analysis is paraphyletic. The N American Stylophorum diphyllum is sister group to the Old World members of Stylophorum and Chelidonium. All American representatives of the subfamily possess distinctive morphological features. This might be the result of Tertiary and Quaternary climatic oscillations leading to severe bottleneck situations in ancient N American populations.