Hairy Grama

Hairy grama, closeup of flowerhead
Species of Conservation Concern
Scientific Name
Bouteloua hirsuta
Poaceae (grasses)

Hairy grama is a native perennial warm-season short grass that forms dense clumps. The narrow leaf blades reach 6 inches long. The flowering stems are rather short, only 4–16 inches high, with 1–3 loosely spaced spikes per stem. The spikes are short (about 1¼ inches long), one-sided, and curving at maturity. The axis of the spike extends about ¼ inch beyond the end of the uppermost spikelet — a distinct, stiff, hairlike projection. The seed heads are densely hairy. 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: Blue grama (B. gracilis) lacks the long-projecting spike axis; the axis of its seed heads does not extend beyond the uppermost spikelet; also, it is less hairy overall, and its seed heads lack the marked hairiness of hairy grama.

Other Common Names
Grama Grass
Mosquito Grass
Eyelash Grass

Height: flowering stems 4–16 inches (sometimes to 2 feet).

Where To Find

Uncommon in the Glaciated Plains in northwesternmost Missouri; there is also a single historical collection that was made from Clark County (in the northeastern corner of the state). The broader range of hairy grama extends in the western United States east to Wisconsin and Louisiana, as well as parts of Canada and Mexico. This species may be grown statewide in cultivation.

Hairy grama is very uncommon in Missouri. It apparently only survives in a single location in Atchison County. Historically speaking, this species has occurred mostly on the loess hill prairies of northwestern Missouri. It has also occurred in sand prairies, which are quite rare in our state, with examples of that habitat surviving only in a few locations near the Mississippi River.

Like many other native prairie grasses, hairy 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.

A species of conservation concern in Missouri, classified as imperiled and vulnerable to extirpation from our state.

Clump forming, native perennial warm-season short grass.

Hairy 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. The unusual and attractive flowering stalks make hairy grama an intriguing addition to landscaping and can be used in dried flower arrangements.

Hairy grama can also be used as a groundcover, especially where drought-tolerant species are needed.

This species is sometimes called mosquito grass because the seed spikes look like mosquito larvae (“wrigglers”).

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.

This species is a dominant grass in the shortgrass prairies of the Great Plains, providing nutrition for antelope, deer, and bison.

In much of its range, hairy grama helps prevent erosion, as it grows in rocky, shallow, and sandy soils and survives extreme drought.

As with blue grama, hairy grama is the larval host plant for certain grassland species of skippers, and many other insects feed on it, too.

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About Wildflowers, Grasses and Other Nonwoody Plants in Missouri
A very simple way of thinking about the green world is to divide the vascular plants into two groups: woody and nonwoody (or herbaceous). But this is an artificial division; many plant families include some species that are woody and some that are not. The diversity of nonwoody vascular plants is staggering! Think of all the ferns, grasses, sedges, lilies, peas, sunflowers, nightshades, milkweeds, mustards, mints, and mallows — weeds and wildflowers — and many more!