Plants annual; cespitose. Culms 20-80 cm, erect or decumbent, sometimes rooting at the lower nodes; internodes densely pubescent to pilose; nodes pubescent to pilose. Sheaths from conspicuously inflated to not inflated, glabrous or pubescent to pilose; ligules 0.5-1 mm; blades 5-15 cm long, 6-20 mm wide, lanceolate, flat, straight, diverging or ascending, velvety pubescent adaxially. Panicles 5-15 cm long, 0.5-4 cm wide, spreading or contracted; rachises hairy; branches (2)3-8(10), 1-4 cm long, 0.4-0.6 mm wide, appressed or reflexed and spreading, velvety pubescent, not winged, with 10-14 spikelets, spikelets in unequally pedicellate pairs at the middle of the branches, solitary distally; pedicels 0.5-1 mm, pilose, apices hairy or glabrous. Spikelets 3-4.5(4.9) mm long, 1.2-1.7 mm wide, elliptic. Upper glumes equaling the lower lemmas, nearly glabrous or sparsely to densely pilose, elliptic, 5-7-veined, acute, unawned; lower lemmas 2.7-4 mm long, 1.2-1.7 mm wide, elliptic, setose to pilose, 5-veined, acute, unawned; lower paleas 1-4 mm, hyaline; anthers absent or 3; upper lemmas 2.3-3.3 mm, elliptic, indurate, dull, rough, occasionally with a few long hairs, acute to rounded, sometimes mucronate; upper paleas indurate. 2n = 36.

Eriochloa lemmonii, a rare species, grows in canyons and on rocky slopes in Pima County, Arizona, Hidalgo County, New Mexico, and adjacent Mexico. The record from Tennessee reflects an introduction. It is not known if the species has persisted in the region.

Eriochloa lemmonii may hybridize with E. acuminata, from which it differs in the frequent presence of lower paleas, raised veins of the upper glumes and lower lemmas, broad, velvety pubescent leaf blades, and blunt spikelets. Reports of E. lemmonii from Texas may be based on hybrids between the two species.

FNA 2003, Gould 1980

Common Name: canyon cupgrass Duration: Annual Nativity: Native Lifeform: Graminoid General: Caespitose annual, stems 20-80 cm, usually decumbent, sometimes erect, rooting at lower nodes; herbage typically pubescent to villous or hirsute, rarely glabrous. Vegetative: Blades thin, flat, 6-20 mm broad, 5-15 cm long, lanceolate, diverging or ascending, velvety pubescent above; ligule of soft hairs 0.5-1 mm; sheath conspicuously inflated to not, glabrous or pubescent to pilose. Inflorescence: Panicle 5-15 cm long, 0.5-4 cm wide, appressed or erect-spreading branches, these subspicate, 2-5 cm long, inflorescence branches and pedicels flattened or angular, more or less densely pubescent with hairs to 4 mm long, often interspersed with shorter hairs; spikelets 3-4.5 mm long, 1-2 mm wide, elliptic; upper glumes equal lower lemmas, nearly glabrous or sparsely to densely pilose, elliptic, 5-7 veined, acute, unawned, lower lemmas 2.5-4 mm long, 1-2 mm wide, elliptic, setose to pilose, 5-veined, acute, unawned. Ecology: Found in sandy washes and depressions, along streams and often on disturbed soils from 2,500-6,000 ft (762-1829 m); flowers August-October. Notes: May hybridize with E. acuminata, differs in the frequent presence of lower paleas, raised veins of upper glumes and lower lemmas, broad, velvety pubescent leaf blades, and blunt spikelets. Ethnobotany: Unknown Etymology: Eriochloa from Greek erion, wool, and chloe or chloa, grass, lemmonii is named for Mt. Lemmon, the location of the type specimen. Synonyms: None Editor: SBuckley, 2010