Data from: Taxonomic study on Japanese Salvia (Lamiaceae): Phylogenetic position of S. akiensis, and polyphyletic nature of S. lutescens var. intermedia

Both Salvia akiensis and S. lutescens (Lamiaceae) are endemic to Japan. Salvia akiensis was recently described in 2014 in the Chugoku (= SW Honshu) region, and each four varieties of S. lutescens distributed allopatrically. Among varieties in S. lutescens, var. intermedia show a disjunctive distribution in the Kanto (=E Honshu) and Kinki (= W Honshu) regions. Recent field studies of S. lutescens var. intermedia revealed several morphological differences between the Kanto and Kinki populations. Here, I evaluated these differences among Salvia lutescens var. intermedia and its allies with morphological analysis and molecular phylogenetic analyses of nuclear ribosomal DNA (internal and external transcribed spacer regions) and plastid DNA (ycf1-rps15 spacer, rbcL, and trnL-F) sequences. Both morphological analysis and molecular phylogenetic analyses showed that S. lutescens var. intermedia from the Kinki region and var. lutescens were closely related to each other. However, var. intermedia from the Kanto region exhibited an association with S. lutescens var. crenata and var. stolonifera, which also grew in eastern Japan, rather than var. intermedia in the Kinki region. These results indicated that S. lutescens var. intermedia is not a taxon with a disjunctive distribution, but a combination of two or more allopatric taxa. Present study also suggested that S. akiensis was most closely related to S. omerocalyx.

阿氏鼠尾草（Salvia akiensis）与黄花鼠尾草（Salvia lutescens）均隶属于唇形科（Lamiaceae），为日本特有物种。阿氏鼠尾草于2014年在日本中国地区（=本州岛西南部）被首次描述；黄花鼠尾草共有4个变种，各变种均呈异域分布。在黄花鼠尾草的各个变种中，中间变种呈现间断分布格局，见于关东地区（=本州岛东部）与近畿地区（=本州岛西部）。近期针对黄花鼠尾草中间变种的野外研究发现，关东与近畿两地的种群间存在多项形态差异。本研究通过形态学分析，以及细胞核核糖体DNA（内部转录间隔区、外部转录间隔区）和质体DNA（ycf1-rps15间隔区、rbcL基因、trnL-F序列）的分子系统发育分析，对黄花鼠尾草中间变种及其近缘类群间的上述差异进行了评估。形态学与分子系统发育分析结果均表明，近畿地区的黄花鼠尾草中间变种与原变种亲缘关系密切；而关东地区的中间变种则与同样分布于日本东部的黄花鼠尾草齿叶变种和匍匐变种聚类，而非与近畿地区的中间变种归为一支。上述结果说明，黄花鼠尾草中间变种并非单一的间断分布类群，而是由两个及以上异域分布类群所组成的复合类群。本研究同时显示，阿氏鼠尾草与奥氏鼠尾草（S. omerocalyx）的亲缘关系最为接近。