Comments: A generally accepted species in a genus of about four species (two others widespread in North America, and another in Asia). Accepted by U.S. Fish and Wildlife Service (federal listing as endangered, 1978), Kartesz (1994 checklist and 1999 floristic synthesis), and Judziewicz et al. (checklist New World grasses, 2000). Described and named by Hitchcock in 1933. LEM 2Feb00.