Species conservation profile and amended distribution of Cousinia knorringiae (Asteraceae), a narrow endemic of the Western Tian-Shan

BACKGROUND: Cousinia knorringiae Bornm. (Asteraceae) belongs to C. sect. Subappendiculatae Tscherneva, a group of the species-rich and taxonomically difficult genus Cousinia Cass. This species is narrowly distributed in the Western Tian-Shan and has been known as endemic to Kyrgyzstan. It inhabits bare rocks and screes at elevations of 1200–1500 m above sea level. This species is of conservation interest because of its small population size and limited distribution. NEW INFORMATION: Cousinia knorringiae is reported for the first time from eastern Uzbekistan on the basis of specimens collected on Ungur-Tepa Mt., a south-western outlier of the Bozbu-Too Mts. (Western Tian-Shan). The conservation status of the species is assessed as Endangered (EN), based on criterion D (estimated population size 200-250 mature individuals), according to the IUCN Red List Categories and Criteria (version 3.1). A new distribution map and a line drawing for C. knorringiae are provided and its type locality is clarified. The new knowledge suggests that the species is endemic to the East Fergana botanical hotspot, which includes a transborder territory shared between Kyrgyzstan and Uzbekistan and should, therefore, be subjected to international conservation measures. The southern extension of Ungur-Tepa Mt. harbours important plant species, which cannot be found elsewhere in Uzbekistan and may, therefore, be proposed for legal protection.