The polyphyletic Caucasus-centred Campanula subg. Scapiflorae (Campanulaceae) revisited with a newly circumscribed C. sect. Tridentatae for its core clade

Campanula L. is among the genera with the highest number of endemics in the Caucasus ecoregion. A group of attractive alpine and subalpine perennial rosette plants with short single-flowered stems centred in the Caucasus has been treated as Campanula subg. Scapiflorae or at other ranks, with considerably varying circumscription and classification. Molecular phylogenetic analysis of three plastid DNA regions (trnK/matK, petD, rpl16) of a strongly extended sampling, comprising 23 of the 27 commonly accepted taxa (85%) with 330 accessions built on and guided by the results of our previous study of the group, confirmed the polyphyly of C. subg. Scapiflorae in any of its circumscriptions. The core clade of the group comprises exclusively endemics and near-endemics of the Caucasus and is treated here as C. sect. Tridentatae in a revised circumscription. The phylogenetic relationships of the disparate other elements of the Scapiflorae group are outlined.风铃草属（Campanula L.）是高加索生态区（Caucasus ecoregion）中特有种数量最多的类群之一。一类集中分布于高加索地区、兼具观赏价值的高山及亚高山多年生莲座状植物，其具短缩的单花茎，曾被归类为风铃草属帚茎亚属（Campanula subg. Scapiflorae）或其他分类等级，其分类范畴与系统划分长期存在显著分歧。本研究依托前期对该类群的研究成果，大幅扩展采样规模，对27个公认类群中的23个（占比85%）共330份标本的3个质体DNA区域（trnK/matK、petD、rpl16）开展分子系统发育分析，结果证实无论采用何种界定方案，帚茎亚属均为多系类群。该类群的核心演化支仅包含高加索地区特有种及近特有种，本研究将其处理为经修订界定的三齿组（C. sect. Tridentatae）。本研究还概述了帚茎亚属类群中其余不同演化组分的系统发育关系。