Lycurus setosus is a species of grass in the Poaceae family, commonly known as the bristly wolfstail. It is found at high elevations in dry areas of the south western United States, as well as in Bolivia and Argentina.
Lycurus setosus is a perennial mountain grass with a tufted habit. The erect stems have several nodes and grow from 30 cm (12 in) to 50 cm (20 in) in height and may have a few branches. The leaf blades are glabrous and grow up to 10 cm (3.9 in) long but only 2 mm (0.1 in) wide. They are rough or bristly and have a white midrib below. The flower panicles are 4 cm (1.6 in) to 8 cm (3.1 in) long and about 8 mm (0.3 in) wide. They are also bristly. It can be distinguished from the rather similar common wolfstail (Lycurus phleoides) by the erect culms, longer ligules and differently shaped tips to the upper leaves.
Lycurus setosus grows at altitudes of between 570 m (1,870 ft) and 3,400 m (11,200 ft). It is found on arid, free draining land, on mesas and rocky slopes. It occurs in the south western states of the United States and in northern Mexico. A separate population occurs in similar habitats in Argentina and Bolivia.