blue grama (eyelash grass)
Bouteloua gracilis Lag. ex Griffiths

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plantinflorescencespikelet and floretillustration

Blue grama grows in and often dominates dry prairies, generally on rocky or clayey soils. The native range of this species extends across the central U.S. from Canada into central Mexico. In Iowa, blue grama is mainly found in the Loess Hills and northwestern counties, but it may be encountered elsewhere as it is sometimes included in native lawn mixes or planted as an ornamental. Blue grama is well suited to these uses because it is a short, mat-forming grass, and the attractive flowering branches often take on a bluish tint as they dry in the fall. The flowering heads with 1 to 3 usually curved, densely flowered, one-sided branches that terminate in a spikelet are distinctive. This species, which flowers from late June to September, is most similar to hairy grama (Bouteloua hirsuta) but is easily distinguished by the straight branches with projecting tips of the latter. Blue grama is palatable and nutritious for livestock and wildlife, providing high quality forage in both the summer and winter. Blue grama is frequently planted as a part of rangeland reclamation efforts and is used in roadside plantings and erosion control projects as well. The Blackfoot tribe of Montana used blue grama to foretell winter weather. Plants with one fruiting branch per stem were believed to indicate a mild winter, while plants with several fruiting branches per stem were taken as a sign that a hard winter was approaching (Blankinship, 1905).

Etymology: The generic name Bouteloua is given in honor of the Spanish botanists Claudio (1774-1842) and Esteban (1776-1813) Boutelou y Soldevilla. Grasses of the genus Bouteloua are often referred to as grama grasses, from Latin gramen = grass. The specific epithet is from Latin gracilis = slender, referring to blue grama’s thin culms.


Plants perennial, densely tufted and mat-forming, often with short rhizomes. Culms 24-70 cm tall. Leaves mostly basal; sheaths smooth to sparsely hirsute near the throat; blades 2-15 (19) cm long, 0.5-2.5 cm wide, short pubescent to scabrous above, smooth to lightly scabrous below; flat to rolled up, especially near the tip, also often wavy or curly toward the tip; ligule of short hairs 0.1-0.4 mm long. Flowering heads 2-8.5 cm long, of 1-3 usually curved, densely flowered branches, these terminal or nearly so; branches 1.5-3.5 (4) cm long, persistent, with 40-130 tightly packed spikelets per branch in a comb-like arrangement, terminating in a spikelet; disarticulation above the glumes. Spikelets 4-7 mm long with 1 perfect and 1 sterile, rudimentary floret, drying light-brown to dark brownish-blue. Glumes smooth to scabrous, sometimes with blister-based hairs along the midvein; lower glumes 1.5-3.5 mm long, upper glumes 3.5-6 mm long, fertile lemmas 3.5-6 mm long, pubescent basally, 5-lobed, central and lateral lobes veined and awned, central awn 1-3 mm long; anthers purple or yellow; rudimentary florets 0.9-3 mm long, with a tuft of hairs below, 3-awned, awns equal, 1-3 mm. Chromosome number 2n = 20, 28, 35, 42, 60, 61, 77, 84.


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