Taxonomic Revision of Trisetum sect. Trisetum (Poaceae: Pooideae: Aveninae) from Eurasia and North Africa
A taxonomic revision of Trisetum Pers. sect. Trisetum is presented. We include descriptions and synonyms of each taxon from a study of 894 vouchers from 45 herbaria. Detailed morphometric descriptions, illustrations, distribution maps, an identification key, and habitat data are given for each taxon. Morphometric variation of the main characters is shown by box plots. Thirty-one names are lectotypified. Two neotypes are designated. We recognize eight species of Trisetum in the section: T. alpestre (Host) P. Beauv., T. altaicum Stephan ex Roshev., T. bertolonii Jonsell, T. flavescens (L.) P. Beauv., T. fuscum Schult., T. glaciale (Bory) Boiss., T. gracile (Moris) Boiss., and T. laconicum Boiss. & Orph. Two infraspecific taxa of T. flavescens are recognized (T. flavescens subsp. flavescens and T. flavescens subsp. griseovirens (H. Lindb.) Dobignard). Six of the eight species of Trisetum sect. Trisetum are endemic to the different European mountain ranges, while T. altaicum grows in the Altai and Tian Shan Mountains, and in the mountains of northern Mongolia and southern Russia, and T. flavescens is widespread in temperate regions of Europe, western Asia, and northern Africa. Vegetative propagation by pseudoviviparism is observed for the first time in specimens of T. flavescens subsp. flavescens.