Centaurea gigantea subsp. davisii (Asteraceae, Cardueae-Centaureinae), a new subspecies from SE Turkey

Abstract

Centaurea s. l., comprising ca. 220 species, is the largest genus in the subtribe Centaureinae in Turkey. For the taxonomic study of Centaurea sect. Cynaroides, an extensive collection from the distribution areas of C. sect. Cynaroides was conducted in SE Turkey. Plant specimens were collected using conventional methods and identified based on reliable taxonomic sources. Moreover, numerous specimens deposited in different herbaria were examined. As a result, Centaurea gigantea Schultz-Bip. ex Boiss. subsp. davisii Negaresh, a new subspecies of C. sect. Cynaroides from the Hakkari Province of SE Turkey, is described and illustrated. It resembles C. gigantea subsp. gigantea, but differs from it by having gray-lanate-floccose phyllaries, yellow flowers, pale yellow anthers, and peripheral florets shorter than the central ones and slightly conspicuous, 4-lobed, with filiform limb lobes. The geographical distribution of the new subspecies and closely related taxa is presented and mapped. In addition, an identification key to all subspecies of C. gigantea is provided. © The Author(s).