Simplified phylogenies of selected groups of eastern Asian-western North American disjunct lineages. Top left: Lysichiton (Araceae). Top right: Paeonia (Paeoniaceae). Lower left: Picea (Pinaceae). Lower right: Cryptogramma (Pteridaceae), illustrating the different phylogenetic patterns in vascular plants. The background shows the polar view of the earth during early Miocene, emphasizing the Beringian biogeographic connection between eastern Asia and western North America. Abbreviations: WNa, Western North America; EAs, Eastern Asia; ENa, Eastern North America; QTP, Qinghai-Tibetan Plateau; SAm, South America. See Wen et al., pp 469–490 in this issue for further explanation. The photograph of Lysichiton americanus was by Gerald and Buff Corsi ©California Academy of Sciences used here with permission. Other photos (Picea glauca, Cryptogramma sitchensis and Paeonia suffruticosa hybrid) were by Stefanie Ickert-Bond.ca. Abbreviations: WNa, Western North America; EAs, Eastern Asia; ENa, Eastern North America; QTP, Qinghai-Tibetan Plateau; SAm, South America. See Wen et al., pp 469–490 in this issue for further explanation. The photograph of Lysichiton americanus was by Gerald and Buff Corsi ©California Academy of Sciences used here with permission. Other photos (Picea glauca, Cryptogramma sitchensis and Paeonia suffruticosa hybrid) were by Stefanie Ickert-Bond. [Detail] ...