Blue grama is a native perennial warm-season short grass that forms dense clumps. The narrow leaf blades reach 6 inches long and often curl, with inrolled margins. The flowering stems are rather short, only 6–12 inches high, with 1–4 loosely spaced spikes per stem. The spikes are short (about 1½ inches long), one-sided, and curve at maturity, resembling an eyebrow. When the seeds have been shed, the spike’s axis looks chaffy because some of the lower floret coverings remain in place. Flower heads develop July–September.
Similar species: Hairy grama (B. hirsuta) is very similar. There are distinct differences in the seed head, including a needle-like extension of the spike axis beyond the section where the seeds are attached (blue grama has no such extension past the uppermost spikelet). Another difference is that hairy grama has seed heads densely hairy, while blue grama lacks such hairiness.
Another similar species, buffalo grass (Buchloe dactyloides), is shorter and does not grow in definite bunches; instead, it creeps widely by stolons (runners), forming dense mats comprising small clumps connected by the stolons. Its leaf blades curl, and the seed heads are compact. It is often grown as a native turf grass.
Height: flowering stems 6–12 inches (sometimes to 2 feet).
Scattered in the Glaciated Plains of westernmost Missouri; introduced in Dunklin and Howell counties (both in southern Missouri). The broader native range of this species is much of the Great Plains, extending from the western United States eastward to Wisconsin and Arkansas, including parts of Canada and Mexico. This species may be grown statewide in cultivation.
Habitat and Conservation
In Missouri, blue grama occurs in upland prairies, especially the loess hill prairies in the far northwestern part of the state. It has also been found along railroads.
Like many other native prairie grasses, blue grama is a warm-season grass that photosynthesizes most efficiently during the hottest part of the summer, a time when cool-season grasses may go dormant.
Status
A Species of Conservation Concern in Missouri, critically imperiled and vulnerable to extirpation from our state.
Clump forming, native perennial warm-season short grass.
Human Connections
Blue grama is an important and widespread range grass in the Great Plains and western United States, where it is considered an excellent native forage grass. It is much too uncommon in Missouri, however, to be considered important for grazing.
People sometimes use this attractive native clump-forming grass in landscape plantings, especially as a specimen plant in rock gardens, native plant gardens, naturalized areas, and places where drought-tolerant plants are required. The unusual and attractive flowering stalks make blue grama an intriguing addition to landscaping and can be used in dried flower arrangements.
Blue grama can also be used as a turf grass; it can be mowed to 2 inches high.
The curious word “grama” came to America from Spanish speakers. The word comes from the Latin gramina, which means “grasses.” Therefore “grama grass” is a redundant expression, basically meaning “grass grass.” For a long time, the grass family was called the Gramineae, using the same Latin root. Botanists moved away from this and other descriptive family names when they decided that all plant family names should be based on the name of a representative genus (that’s why the grass family is now the Poaceae, after genus Poa). You might occasionally see the word “graminoid,” which means “grasslike,” used for plants like sedges and rushes, which are grasslike but not in the grass family.
Ecosystem Connections
In some parts of America, blue grama is an important soil binder, enduring severe drought and recovering rapidly when moisture returns; thus it helps prevent soil erosion.
This species is a dominant grass of North America’s shortgrass prairies and an important component of midgrass/mixed grass and tallgrass prairies, providing nutrition for antelope, deer, and bison. Its native range extends from Alberta, Canada, into Mexico.
A number of skippers use blue grama as a larval host plant. Many other insects feed on it, too.
