At one time, Six-Weeks Fescue was classified as Festuca octoflora. This grass and other annual Festuca spp. have been reassigned to the Vulpia genus. These other species occur mainly in the Western states and their spikelets have longer awns than those of Six-Weeks Fescue. In general, these drought-adapted grasses have slender leaves and a short stature. Six-Weeks Fescue is rather variable across its range and different varieties have been described. The typical variety differs from var. tenella (described above) by having spikelets with longer awns (> 3 mm.), while var. glauca has spikelets without awns or shorter ones (< 2 mm.); also the smaller glumes of var. glauca are shorter (< 3 mm.) than those of var. tenella. Sometimes the lemmas of the typical variety and var. tenella are slightly pubescent, rather than hairless. However, this is difficult to observe without a 10x hand lens.