Poa densa (Poaceae), an overlooked Turkish steppe grass, and the evolution of bulbs in Poa

Poa densa Troitsky is a characteristic species of the high steppe to low alpine vegetation of Turkey. It was overlooked in the Flora of Turkey, and although subsequently reported from a few stations in W part of C Anatolia, is actually relatively common and widespread across the semi-arid C and N steppes. Here we provide a key to related species, a full description, photographs, 2C value of nuclear DNA content, and a distribution map, and discuss its classification in the genus. The synonym Festuca conferta is lectotypified. DNA phylogenetic analysis and morphology data indicate P. densa is allied to species of P. subg. Poa sect. Macropoa, rather than to the P. bulbosa complex of P. subg. Ochlopoa sect. Arenariae, and support multiple origins of the basal bulb in the genus Poa.