Plants perennial; rhizomatous, not cespitose. Culms 5-42 cm tall, 0.5-1 mm thick, decumbent near the base, forming dense mats; internodes glabrous, slightly nodulose. Sheaths shorter or longer than the internodes, glabrous; ligules 0.1-1(1.8) mm, membranous, truncate, occasionally lacerate; blades 0.4-6 cm long, 0.5-1.4 mm wide, involute, glabrous, smooth or scabridulous adaxially. Panicles 1-9 cm long, 0.1-0.6 cm wide, contracted, not dense, usually partially included in the upper leaf sheaths; primary branches 0.2-3 cm, usually closely appressed at maturity, rarely diverging up to 40° from the rachises; pedicels 0.2-3.6 mm, setulose. Spikelets 2.6-4.2 mm, occasionally with 2 florets. Glumes subequal, 1.1-3.6 mm, from 1/2 as long as to equaling the lemmas, light green, 1(2-3)-veined, acute, unawned; lemmas 2.6-3.2(4.2) mm, lanceolate, dark greenish or mottled, glabrous or the calluses and margins appressed-pubescent, hairs to 0.3 mm, apices scabridulous, attenuate, usually mucronate, mucros 0.1-0.3 mm; paleas 2.1-3.3 mm, lanceolate, smooth or scabridulous, acute; anthers 0.7-1.4 mm, yellow to purplish. Caryopses 1.1-1.5 mm, ellipsoid to ovoid, brownish. 2n = 60, 70-72.

Muhlenbergia repens grows in open, sandy meadows, canyon bottoms, calcareous rocky flats, gypsum flats, and on rolling slopes and roadsides, at elevations of 100-3120 m. Its range extends from the southwestern United States to southern Mexico.

Common Name: creeping muhly

Duration: Perennial

Nativity: Native

Lifeform: Graminoid

General: Low rhizomatous perennial grass, forming dense mats; stems 5-42 cm tall, 0.5-1 mm thick, decumbent near base; internodes glabrous, shiny.

Vegetative: Blades short, arcuate, involute, glabrous beneath, 0.5-6 cm long, 0.5-1.5 mm wide; ligule membranous, truncate, often split down the middle, 0.1-1 mm; sheaths glabrous to scabrous.

Inflorescence: Contracted panicle or raceme, 1-9 cm long, less than 5 mm wide, loosely flowered, pale or tawny; primary branches 0.5-3 cm, closely appressed at maturity; 2-30 spikelets, 2-5 mm, with 1, occasionally 2 florets; glumes subequal, slightly more than half to almost as long as the lemma, glabrous or scabrous, broadly acute at apex; lemma smooth or scaberulous, awnless or mucronate; palea equaling the lemma.

Ecology: Found on canyon bottoms, dry slopes, and open mesas from 3,500-7,000 ft (1067-2134 m); flowers August-November.

Distribution: AZ, se UT, NM, w TX, OK, south to s MEX.

Notes: Muhlenbergia is a large and diverse genus primarily distinguished by having single-flowered spikelets with unequal glumes. M. repens is similar to other creeping muhlys, but pay attention to the few-flowered raceme-like panicle with awnless spikelets to identify this species. The tightly clumped, short blades that curve away from the stem are also distinctive.

Ethnobotany: Unknown

Etymology: Muhlenbergia is named for Gotthilf Heinrich Ernst Muhlenberg (1753-1815) a clergyman and botanist from Pennsylvania; repens means having creeping and rooting stems.

Synonyms: None

Editor: SBuckley 2010, AHazelton 2015