This clade, generally undervalued by recently published phylogenetic trees (up to three species in Roquet et al. (2008), shows strong support for the crown group and presently contains six species and 10 subspecies of bluebells occurring in the Asian part of Turkey and Caucasus, C. persicifolia extending its range to central and southern Europe. Except for the two early diverging biennials C. psilostachya and C. pterocaula, all species in this clade are perennial. Campanula psilostachya is a Turkish endemic that was at some time of its taxonomic history included in Asyneuma, based on its small funnel shaped corolla with divided lobes (Boissier 1875), or considered to be morphologically related to C. americana (Crook 1977). It presently resides in clade Cam03 so that both hypotheses are not supported by the current gene tree, which rather suggests strong relationships with C. pterocaula, another Turkish species with broadly campanulate flowers. The attractive species C. persicifolia and C. latiloba also share large campanulate corollas, and mainly differ by the cauline leaf width (linear in C. persicifolia vs. broadly lanceolatate in C. latiloba), the capsule dehiscence mechanism (apical in C. persicifolia vs. median in C. latiloba) and the size of their distribution range. While C. persicifolia is widely distributed throughout Europe, C. latiloba is a Euxine element of Turkey. Both species are frequently cultivated in gardens. The use of C. persicifolia as an ornamental plant dates back to the 16th century (Crook 1977). Our analysis further depicts strong sister relationships between C. stevenii (4 subspecies included) and C. phyctidocalyx, both species with usually one-flowered ascending-erect stems, a long ribbed calyx and a funnel-shaped, moderately-sized corolla, differing only by the ovary shape. Interestingly, two additional subspecies of C. stevenii (subsp. albertii and subsp. turczaninovii) fall in the respective clades Cam04 and Cam06, overall suggesting the polyphyly of C. stevenii in its current concept.

From: Mansion & al. (2012: 11)

References

Boissier E. 1875: Flora Orientalis. Genève: Georg, H.

Crook H.C. 1977: Campanulas - Their cultivation and classification. London Country Life.

Mansion G., Parolly G., Crowl A.A., Mavrodiev E., Cellinese N., Oanesian M., Fraunhofer K., Kamari G., Phitos D., Haberle R., Akaydin G., Ikinci N., Raus T. & Borsch T. 2012: How to Handle Speciose Clades? Mass Taxon-Sampling as a Strategy towards Illuminating the Natural History of Campanula (Campanuloideae). – PLoS ONE 7 (11).

Roquet C., Saez L., Aldasoro J.J., Susanna A., Alarcon M.L. & al. 2008: Natural delineation, molecular phylogeny and floral evolution in Campanula. – Syst. Bot. 33: 203–217.