New Approach to the Systematics of the Section (, Iridaceae): What Does Chloroplast DNA Sequence Tell Us?

sect. comprises rhizomatous perennials distributed in the north temperate zone of Eurasia. The systematics of the section are currently based on morphology, and the phylogenetic relationships within it still remain unclear. In the framework of systematics, we conducted molecular and morphological analyses of the currently recognized . sect. species to elucidate the taxonomic composition and relationships within the section. The phylogenetic reconstructions based on sequence variation of four noncoding chloroplast DNA regions support the monophyly of . sect. , which includes , while var. belongs to sect. . The proposed novel classification of . sect. recognizes three series: an autonymic series with , , and I and two unispecific series (. ser. with and . ser. with ). In addition, the taxonomic statuses of , , , , , , and are clarified herein. We provide a revised taxonomic treatment for . sect. , including notes on the types; updated information on species synonymy, distributions, habitats, and chromosome numbers; and a new identification key to the species. Three lectotypes are designated here.