Blue grama is a perennial grass that is native to North America. Classified under the scientific name Bouteloua gracilis, this grass is characterized by its gray-green foliage and its bent and flattened inflorescence. This grass can grow up to 3 feet (0.91 m) tall, and its roots have a maximum depth of around 6.5 feet (2 m). It typically grows in clumps with a spread of up to 1 foot (0.3 m). Designated in 1987 as the Colorado state grass, it is also known under the names signal-arm grass and mosquito grass.
Typically found in the deserts, meadows, and prairies across the middle to southern regions of the United States, the blue grama grass is also abundant in the prairie provinces of Alberta to Manitoba in Canada, as well as in Mexico. This grass is not hardy in the colder areas of North America, as it can only tolerate temperatures down to 14 ºF (-10 ºC). The blue grama is listed as endangered in the state of Illinois in the United States.
The active growth periods of blue grama are in summer and fall, which is also usually the time when its yellow flowers bloom. Its hermaphroditic flowers are pollinated with the help of the wind, forming highly abundant brown seeds. The curved seed heads are brownish purple, resembling human eyebrows perched on top of wiry stems. Propagation is primarily by seed, wherein the seeds are dispersed by the wind and other natural dispersal agents, such as insects, birds, and grazing mammals. When under cultivation, they are more readily established through vegetative reproduction via tillering.
As a low-maintenance grass, it can grow in fine, medium, or coarse soils as long as there is ample moisture and good drainage. Blue grama prefers lime-free soils and can tolerate soils with low nutrients better than acidic ones. It needs to be exposed fully to the sun and cannot grow in the shade. This grass also has a high drought and fire tolerance but can be susceptible to rust, fungal spots, and root rot. It can also withstand close grazing.
Primary uses of this grass are as a fodder product for livestock, ground cover, and for erosion control when mixed with other grasses. The grass is also used in making baskets and dried flower arrangements. Other uses of the stems are as material for combs or brooms and grinding the seeds into powder to eat as mush or to make bread.