Abstract:

Caragana has a temperate Asian distribution. Based on the phylogeny and 13 distributional areas of this genus, its ancestral area was studied via the ancestral area analysis suggested by Bremer (1992), Ronquist (1994) and Hausdorf (1997). The results indicate that three areas, Far East-Northeast China, Altai-Sayan and North China-Qinling Mountains (Mts) are likely the ancestral areas. Linking to the viewpoints of the Holarctic origin for north temperate flora, Far East-Northeast China seems more likely to be the ancestral area. According to the three ancestral areas isolated geographically and the analysis in the present study, as well as former biogeographical analysis of this genus, it is suggested that Caragana speciation is mainly in the mode of vicariance rather than dispersal, and dispersed is often in short distance.

Key words: Caragana, ancestral area, distribution pattern, evolution