Sexual reproduction in Taraxacum sect. Borealia (Asteraceae, Crepidinae) first documented in the Russian Far East

Modes of reproduction vary considerably in the genus Taraxacum. In particular, the extent and distribution of sexuality are decisive criteria for the evaluation of variation and the taxonomic conclusions in this complicated genus. Taraxacum sect. Borealia is widespread in the Arctic and Subarctic regions of the Asiatic part of Russia, but sexual reproduction has not been known to occur there, unlike T. sect. Arctica with a number of sexually reproducing species in the continental Far East. A detailed analysis of the herbarium material of Taraxacum kolymense Khokhryakov, using pollen size analysis and achene set examination, revealed sexuality in this distinctive member of T. sect. Borealia. The lectotype is selected for T. kolymensefrom a rich type gathering consisting of seven herbarium specimens, and a new consolidated description was compiled.