Taxonomic revision of the Stipa lipskyi group (Poaceae: Stipa section Smirnovia) in the Pamir Alai and Tian-Shan Mountains

The Stipa section Smirnovia Tzvel. includes 32 taxa. Of this number, 18 taxa, with glabrous (smooth or scabrous) awn columns, belong to the Stipa lipskyi group, which is the object of the present study. The centre of diversity of the studied group is located in the mountains of Middle Asia (Pamir Alai and Tian-Shan). Based on the examination of a large number of herbarium specimens (over 550 sheets), field observations, scanning electron microscopy observation of lemma micromorphology and statistical analysis of macromorphological characters, 12 taxa at the specific level were recognized on the area studied. Three species of hybrid origin, Stipa × tadzhikistanica M. Nobis, S. × brevicallosa M. Nobis, and S. × hissarica M. Nobis, as well as the variety S. lipskyi var. pilosivaginata M. Nobis, were described as new to science. Additionally, lectotypes for S. karataviensis Roshev. and S. longiplumosa Roshev. were designated and a new combination Stipa macroglossa subsp. kazachstanica (Kotuch.) M. Nobis was proposed. Numerous new localities, often far from the previously known distribution area, were reported for several species. Illustrations and a key to species and varieties are provided in addition to complete descriptions including information on nomenclatural types, synonymies, distributions, habitat and specimens examined.