Flower:

Raceme-like cluster on the upper stem, 1 to 3 branches, usually 2, rarely 4 to 6. Branches are up to 1¾ inches long and short-stalked, the terminal branch erect to spreading, the lateral branches ascending to slightly drooping.

A branch has 40 to 130 spikelets (flower clusters), arranged on one side of the rachis (stalk), tightly packed in 2 rows. Spikelets are green to purple, 4 to 6 mm long, each with one sterile and one fertile floret. At the base of a spikelet is a pair of bracts (glumes) that are smooth to rough textured, often sparsely long-hairy along the midvein, the lower glume awl-shaped, 1.5 to 3.5 mm long, the upper glume lance-shaped, 3.5 to 6 mm long. The fertile floret is surrounded by a pair of bracts (lemma and palea), the lemma about as long as the upper glume, 5-lobed, short-awned on each lobe, short-hairy at least near the base, with longer hairs along the midvein; the palea is slightly shorter than the lemma and notched at the tip. Sterile lemmas are stalked, long-haired at the base, 3-lobed, 3-awned, shorter than the fertile lemmas but longer awned.

Leaves and stems:

Leaves are mostly basal with 2 or 3 alternate on the stem, 1 to 6 inches long, about 2 mm wide, flat in cross-section but often curled, the edges rolled up (involute) especially when dry, usually short-hairy near the base, sometimes with a few long, white hairs along the edge. Sheaths are hairless to sparsely hairy on the surface. Nodes are smooth to minutely hairy. The ligule (membrane where the leaf joins the sheath) is a fringe of white hairs .1 to .4 mm long.

The outer edge of the ligule (collar) is often lined with long, white hairs. Stems are erect, or horizontal then rising at the lower node (geniculate), hairless, rooting at the nodes, forming dense clumps and may form mats from short rhizomes.

Fruit:

Spikelets ripen to light brown, the florets dropping at maturity, leaving the glumes behind. As the florets mature and the spike branch dries, it curls back (recurves) and persists into winter. Grains (seeds) are oblong-elliptic and brown, 2.5 to 3 mm long.

Notes:

A dry prairie species of the Great Plains and western states and an important forage grass, Blue Grama is also popular as an ornamental grass due to the recurved spikes and dense clumps of curly leaves. It is easily confused with the related Hairy Grama (Bouteloua hirsuta), which is hairier overall, has shorter spikes with fewer spikelets per branch (20 to 50), and the branch rachis extends well past the last spikelet, looking like a spine at the tip (see comparison photo below).