Taxonomic revision of Stipa section Smirnovia and section Subsmirnovia (Poaceae)

A comprehensive taxonomic revision of Stipa section Smirnovia and section Subsmirnovia is proposed on the basis of a critical morphological analysis of extensive herbarium material. The morphological variation was analysed by the study of 702 vouchers from 32 different herbaria. The revision of section Smirnovia results in the recognition of 18 taxa (13 species and five subspecies) characterized by a unigeniculate awn with a glabrous to pilose column, a plumose seta and an ovary with two styles. The taxa of section Smirnovia are mainly distributed in central Asia. Section Subsmirnovia comprises only one species, S. gaubae, restricted to north-west Iran and southern Azerbaijan. Stipa gaubae shares the same awn features as section Smirnovia, but is clearly differentiated by its longer ligules and three-styled ovary. Keys to species and subspecies, and synonymy, detailed morphometric descriptions, illustrations and distribution maps are provided for most of the taxa. Nine lectotypes are designated. (C) 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 167, 394448.