Phylogenetic relationships among Old World Ruellia L.: a new classification and reinstatement of the genus Dinteracanthus Schinz

The genus Ruellia (Acanthaceae) consists of some ca. 350 species that are concentrated in tropical and subtropical regions of the world. Old World Ruellia have never been the focus of explicit phylogenetic study, yet comprise the earliest diverging lineages in the genus and contain upwards of 100 species. We sampled 52 accessions representing 29 OW species of Ruellia for phylogenetic analysis. Results yielded five clades that were strongly supported and marked by morphological synapomorphies. Analyses additionally recovered a newly recognized lineage within the tribe Ruellieae, a small radiation of plants in the deserts of Namibia and Angola, and the name Dinteracanthus is available for reinstatement. Divergence time analysis using a primary fossil calibration revealed relatively young estimates for crown ages of all five clades of OW Ruellia (2.5 Ma ‐ 630,000 ypb) as well as for Dinteracanthus (2.0 Ma). Ancestral state reconstruction of pollination systems among OW Ruellia suggest a mi...

爵床科（Acanthaceae）芦莉草属（Ruellia）约包含350个物种，集中分布于全球热带及亚热带区域。旧大陆芦莉草类群从未成为专门系统发育研究的核心对象，但该类群构成了芦莉草属最早分化的演化支，且包含逾100个物种。本研究采集了代表旧大陆29个芦莉草物种的52份实验材料用于系统发育分析。结果得到5个得到强力支持的演化支，各支系均具有形态学共有衍征。此外，本研究在芦莉草族（Ruellieae）中发现了一个新界定的演化支：一类分布于纳米比亚与安哥拉荒漠的小型辐射演化植物类群，其可用学名丁特棘属（Dinteracanthus）可予以恢复使用。基于主要化石校准的分化时间分析显示，旧大陆芦莉草5个演化支的冠群分化时间均相对较晚（250万年至63万年前），丁特棘属的冠群分化时间亦为200万年。对旧大陆芦莉草传粉系统的祖先状态重建结果显示……