2. Bouteloua gracilis (Kunth) Lagasca ex Griffiths, Contr. U. S. Natl. Herb. 14: 375. 1912.
格兰马草 ge lan ma cao
Chondrosum gracile Kunth, Nov. Gen. Sp. 1: 176. 1815 ["1816"]; Actinochloa gracilis (Kunth) Willdenow ex Roemer & Schultes; Atheropogon gracilis (Kunth) Sprengel; Eutriana gracilis (Kunth) Trinius.
Perennial. Culms densely tufted, erect, 15–60 cm tall. Leaf sheaths glabrous, in tight bundles at culm base; leaf blades flat or involute, 3–10 cm, 1–2 mm wide, usually glabrous. Inflorescence of (1 or)2(–4) distant racemes; racemes 2.5–5 cm, falcate at maturity, persistent, spikelets numerous, densely crowded, pectinate; rachis not extendedbeyond uppermost spikelet. Spikelets 5–6 mm; glumes lanceolate, persistent; lower glume linear-lanceolate, ca. 3.5 mm; upper glume lanceolate, 3.5–6 mm, sparsely villous on keel; lemma of fertile floret 5–5.5 mm, dorsally villous, lateral veins extended into 3 short awns at apex, intermediate lobes acute; 2nd floret ca. 2 mm, densely long-villous at rachilla apex, cleft to the base, lobes rounded, awns 3, scabrous, ca. 5 mm; 1 or 2 additional broad awnless rudiments sometimes present. Fl. and fr. summer to autumn. 2n = 28, 35, 42, 61, 77.
Cultivated in China [native to North America (including Mexico)].
This is a valuable forage grass native to the North American prairie (Blue Grama).