Data from: Phylogenetics, delimitation and historical biogeography of the pantropical tree genus Thespesia (Malvaceae, Gossypieae)

Thespesia consists of 16 species of trees and shrubs from Southeast Asia–Oceania, Africa and America, the most well known being T. populnea, a small tree of tropical coastal areas around the world. Phylogenetic relationships in the genus and among its allies in tribe Gossypieae were inferred using three plastid and two nuclear regions to ascertain its generic delimitation and explore its biogeographical history. Maximum-likelihood and Bayesian analyses confirmed that Thespesia is not monophyletic and, based on these results, Azanza is reinstated to accommodate the two species previously placed in Thespesia section Lampas. Dating analyses and ancestral range estimation indicated that Thespesia s.s. most likely originated in Southeast Asia–Oceania c. 30 Mya, but extant species did not begin to differentiate until the late Miocene. Two dispersal events, one into Africa c. 11 Mya and another into America (Antilles) c. 9 Mya, gave rise to the African and the Greater Antillean endemics, respectively. The two most widespread hydrochorous species, T. populnea and T. populneoides, originated in Southeast Asia–Oceania from where they spread to other parts of the world. Our analysis also indicated a much earlier origin than previously reported for Eumalvoideae and its tribes, suggesting that vicariance might have had an important role early in the history of these groups.桐棉属（Thespesia）包含分布于东南亚-大洋洲、非洲及美洲的16种乔木与灌木，其中最广为人知的是杨叶肖槿（Thespesia populnea）——一种遍布全球热带沿海区域的小乔木。本研究借助3个质体（plastid）与2个核基因区域，对桐棉属及其在棉族（Gossypieae）中的近缘类群的系统发育关系进行推断，以明确该属的分类界定并探讨其生物地理演化历史。最大似然法（Maximum-likelihood）与贝叶斯分析均证实，桐棉属并非单系类群；基于此结果，研究恢复了Azanza属（Azanza）的分类地位，用以容纳此前被归入桐棉属Lampas组（section Lampas）的2个物种。分化年代分析与祖先分布区重建结果显示，狭义桐棉属（Thespesia s.s.）最可能起源于东南亚-大洋洲区域，距今约30百万年（Mya），但现存类群直至晚中新世才开始分化。两次长距离扩散事件分别促成了非洲与大安的列斯群岛特有类群的形成：一次于约11百万年前扩散至非洲，另一次于约9百万年前扩散至美洲安的列斯群岛（Antilles）。分布最广泛的两种水媒传播物种（hydrochorous）——杨叶肖槿（Thespesia populnea）与Thespesia populneoides，起源于东南亚-大洋洲区域，并由此扩散至全球其他区域。本研究同时发现，真锦葵亚科（Eumalvoideae）及其各族的起源时间远早于此前报道，这表明地理分隔分化（vicariance）在这些类群的早期演化历史中或发挥了关键作用。