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

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 World Turpinia 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.

传统上，省沽油科（Staphyleaceae）包含3个分布于温带与热带的乔木和灌木属：野鸦椿属（Euscaphis Siebold & Zucc.）、膀胱果属（Staphylea L.）以及山香圆属（Turpinia Vent.）。该属级划分曾得到形态学证据的有力支持，但近期一项基于4个叶绿体基因与核内转录间隔区（internal transcribed spacer, ITS）的分类研究，将膀胱果属、野鸦椿属以及新世界山香圆归入广义膀胱果属（Staphylea s.l.），而将旧世界山香圆独立为达林普利亚属（Dalrympelea Roxb.）。本研究的目标共三项：（1）利用2个核基因标记与6个叶绿体基因标记，解析省沽油科内的系统发育关系；（2）探寻支撑各主要演化支的形态共衍征；（3）探讨本研究结果对属级分类界定及生物地理学研究的启示。本研究的系统发育结果显示，省沽油科可划分为5个主要演化支：（1）旧世界山香圆演化支；（2）新世界山香圆演化支；（3）仅分布于旧世界的膀胱果属演化支；（4）涵盖所有新世界物种与其余旧世界物种的亚洲-北美分布膀胱果属演化支；（5）野鸦椿属演化支。在膀胱果属与山香圆属各自的两个演化支中，传统上用于界定属级类群的形态特征可能存在趋同演化现象。在本研究检测的诸多形态特征中，我们发现花粉并无分类学信息价值；叶齿特征与表皮蜡质特征分别对传统的膀胱果属与山香圆属的界定仅能提供有限支持；且旧世界山香圆的花瓣长度（即花大小）显著小于新世界山香圆。在生物地理学层面，本研究结果支持北美东部与喜马拉雅地区之间存在一种罕见的分布间断格局。