A New Species of Ptilagrostis (stipeae, Poaceae) from Qinghai-Tibet Plateau

A new species, Ptilagrostis arcuata, from Qinghai-Tibet Plateau is described and illustrated. It is easily distinguished from the similar P. concinna by its arcuate or heliciform awns with golden yellow or pale yellow hairs, narrower basal leaves, and absence of bracts below the panicles. The chromosome number of the new species is 2n=22, karyotype 2n=22=14m+6sm+2st.