LAUSR

Abstract A taxonomic revision of Trisetum sect. Sibirica is presented. We include descriptions and synonyms of each taxon from a study of 450 vouchers from 35 herbaria. Detailed morphometric descriptions, illustrations, distribution maps, identification key, and habitat data are given for each taxon. An identification key for all taxa of Trisetum sect. Sibirica is provided. Morphometric variation of the main characters is shown by box plots. Six names are lectotypified. We recognize six species of Trisetum in the section: T. aeneum, T. bifidum, T. henryi, T. scitulum, T. sibiricum, and T. turcicum. Two infraspecific taxa of T. sibiricum are recognized (T. sibiricum subsp. sibiricum and T. sibiricum subsp. litorale), while T. pauciflorum, T. sikkimense, and T. umbratile are reduced to synonyms of T. sibiricum subsp. sibiricum. Four of the six species of Trisetum sect. Sibirica are endemic to Eastern Asia and New Guinea, while T. turcicum grows in Turkey, the Caucasus, and Northern Iran, and T. sibiricum is widespread from Eastern Europe to Alaska and Canada.