A Taxonomic Revision of Coptis quinquefolia var. shikokumontana (Ranunculaceae)

Abstract

The phylogenetic relationships of Coptis quinquefolia Miq. and its related species (Ranunculaceae) were analyzed using nuclear DNA (ITS) and chloroplast DNA (trnL intron and trnL–trnF intergenic spacer) along with morphological variation to clarify the taxonomic status of Coptis quinquefolia var. shikokumontana. The results suggest that plants of the genus Coptis in Shikoku previously classified as C. quinquefolia var. shikokumontana include three taxa; C. quinquefolia var. shikokumontana, C. quinquefolia var. quinquefolia, and C. minamitaniana. In addition, it was also suggested that there is an intermediate type presumed to be a hybrid between the latter two taxa. In Shikoku C. quinquefolia var. shikokumontana is found in the mountains of the central part of Shikoku Island, from Naka-cho (Mt. Tsurugi-san), Tokushima Pref. to Saijo-shi (Mt. Kamega-mori), C. quinquefolia var. quinquefolia is widely distributed in Tokushima, Ehime and Kochi Pref. and C. minamitaniana is known only from the lowlands of central Kochi Pref. Coptis quinquefolia var. shikokumontana is taxonomically revised and additionally circumscribed in this paper.