J Syst Evol ›› 2017, Vol. 55 ›› Issue (2): 124-141.DOI: 10.1111/jse.12236

• Research Articles • Previous Articles     Next Articles

A molecular phylogeny of Staphyleaceae: Implications for generic delimitation and classical biogeographic disjunctions in the family

AJ Harris1, Ping-Ting Chen2, Xin-Wei Xu3, Jian-Qiang Zhang4, Xue Yang5, and Jun Wen1*   

  1. 1Department of Botany, National Museum of Natural History, MRC-166, Smithsonian Institution, Washington, DC 20013-7012, USA
    2Institute of Agricultural Economy and Information, Hubei Academy of Agricultural Sciences, Wuhan 430064, China
    3National Field Station of Freshwater Ecosystem of Liangzi Lake, College of Life Sciences, Wuhan University, Wuhan 430072, China
    4College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
    5Agriculture School, Kunming University, Kunming 650214, China
  • Received:2016-06-16 Published:2017-03-08

Abstract: Staphyleaceae traditionally comprises three genera of temperate and tropical trees and shrubs: Euscaphis Siebold & Zucc., Staphylea L., and Tuprinia Vent. These genera are clearly supported by morphology, but a recent classification based on four chloroplast genes and nuclear ITS treats Staphylea, Euscaphis, and New WorldTurpinia in Staphylea s.l. and Old World Turpinia in Dalrympelea Roxb. In this study, our objectives were to (1) resolve the phylogenetic relationships within Staphyleaceae using two nuclear and six chloroplast markers, (2) explore morphological synapomorphies that support major clades, and (3) discuss the implications of our results on generic delimitation and biogeography. Our phylogenetic results show five major clades in Staphyleaceae: (1) Old World Turpinia, (2) New World Turpinia, (3) a clade of exclusively Old World Staphylea, (4) an Asian-North American clade of Staphylea comprising all New World species and the rest of the Old World ones, and (5) Euscaphis. Within the two clades each of Staphylea and Turpinia, morphological features traditionally used for delimiting the genera may exhibit convergence. Among morphological features examined in this study, we found that pollen is not taxonomically informative, features of leaf teeth and epicuticular waxes show limited support for the traditional genera of Staphylea and Tuprinia, respectively, and petal length (i.e., flower size) is significantly smaller in Old World Turpinia compared to New World Turpinia. With respect to biogeography, our results support a rare disjunction between eastern North America and the Himalayas.

Key words: Amphi-Pacific disjunction, Asian-North American disjunction, biogeography, Dalrympelea, generic delimitation, Euscaphis, Staphylea, Turpinia