Plants perennial; rhizomatous, not cespitose. Culms 10-45 cm tall, 0.3-0.5 mm thick, erect or decumbent; internodes hirsute and strigose below the nodes. Sheaths shorter than the internodes, hirsute; ligules 0.2-0.6 mm, margins hyaline, apices truncate to obtuse, erose, ciliate; blades 0.5-4(5) cm long, 0.6-1.5(2.2) mm wide, awl-shaped, flat near the base, becoming slightly involute distally, strigose to scabrous abaxially, hirsute adaxially. Panicles 2-10 cm long, 0.2-1 cm wide, contracted, not dense; primary branches 0.3-2.5 cm, ascending to appressed; pedicels 0.1-3 mm. Spikelets 2.8-4 mm. Glumes equal, 2.5-4 mm, 1-veined, veins scabridulous, apices acute; lemmas 2.8-4 mm, lanceolate, hairy on the lower 3/4, hairs to 1.5 mm, tawny, midveins scabridulous distally, apices acuminate, awned, awns usually 1-6(12) mm, delicate, straight; paleas 2.8-4 mm, lanceolate, intercostal region tawny pubescent on the basal 3/4; anthers 1.2-1.6 mm, yellowish-purple. Caryopses 2-2.4 mm, fusiform, brownish. 2n = unknown.
Muhlenbergia curtifolia grows on damp ledges and in rock crevices of vertical cliffs, and beneath large calcareous boulders above the canyon floor, at elevations of 1600-2750 m, in the southwestern United States. It resembles M. thurberi, differing in its flatter leaf blades and shorter ligules and anthers. It also tends to grow in more mesic habitats than M. thurberi.
FNA 2007, Field Guide to Forest & Mtn. Plants of N AZ 2009
Common Name: Utah muhly Duration: Perennial Nativity: Native Lifeform: Graminoid General: Perennial bunchgrass, 10-50 cm tall, with contracted panicles and long awns to 25 mm. Vegetative: Blades 1-4 cm long, 1 mm wide, flat near the base, slightly rolled in distally, coarse erect hairs above, strigose below; ligules <1 mm long, with truncate apices, ciliate; stems 10-45 cm tall, erect or decumbent, sheaths shorter than internodes, with coarse erect hairs. Inflorescence: Panicles 2-10 cm long, 1 mm wide, contracted but not dense; primary branches 3-25 mm long, appressed or ascending; spikelets 3-4 mm long, usually 1-flowered, sometimes 2-flowered; glumes equal, 2-4 mm, 1-veined, with acute apices; lemmas 3-4 mm, hairy on most of the lower portion with hairs 1 mm long, awned with awns 1-6 mm long, straight; paleas 3-4 mm, pubescent on most of the lower portion; anthers 1 mm long. Ecology: Found in moist areas such as in rock crevices or against boulders in canyons from 5200-9000 ft. (1600-2750 m); flowers June-Oct. Distribution: Arizona, Utah, and Nevada Notes: Is similar to M. thurbia but has flatter leaves and shorter anthers and ligules than M. thurbia and grows in wetter environments. It is also similar to M. pauciflora but has pubescent lemmas and grows in wetter environments than M. pauciflora. Ethnobotany: Unknown Etymology: Muhlenbergia is named for Gotthilf Heinrich Ernst Muhlenberg (1753-1815) a clergyman and botanist from Pennsylvania; Editor: LKearsley, 2012