Culms (6)10-30(40) cm tall, (0.3)0.6-1(2.5) mm thick, glabrous or hispidulous. Ligules 2-3.5 mm; blades (1)3-6(9) cm long, (0.5)1-1.5(2.5) mm wide, both surfaces sparsely pilose or glabrous, grayish-green. Panicles 1-4(6) cm; branches with 3-9 shortly pedicellate spikelets. Spikelets 6-12(15) mm, with (5)6-12(20) florets. Glumes exceeded by the lowest florets, pale; lower glumes 4-7 mm; upper glumes 4-7 mm; lemmas 3-6 mm, green or purplish-green when young, becoming stramineous at maturity, awned, awns 0.5-2.5 mm, apices acute, entire or bidentate, teeth 0.3-0.5 mm; anthers usually 3, 0.3-1 mm. Caryopses 1-1.5 mm. 2n = 16.

Common Name: hairy woollygrass

Duration: Perennial

Nativity: Native

Lifeform: Graminoid

General: Weakly-rooted perennial grass, with low basal tufts of leaves and tall, erect, nearly leafless stems emerging from the basal tufts and topped with short, dense contracted panicles. Stems 10-30 cm tall, 0.5-1 mm thick, glabrous to hispidulous, usualy with a single cauline leaf.

Vegetative: Blades 3-6 cm long, 1-2 mm wide, flat or folded, often short and thinly pilose; ligules 2-3.5 mm.

Inflorescence: Contracted panicles or racemes 1-4 cm long, with 3-9 shortly pedicellate spikelets; spikelets 6-12 mm with 6-12 closely imbricate florets, the distal florets staminate or sterile; disarticulating above the glumes and between the florets; glumes pale in color, subequal, and exceeded by lowest florets, 4-7 mm; calluses with tufts of hairs; lemmas 5-6 mm long, ciliate-pubescent on the nerves near the base, green purplish when young, becoming straw colored at maturity, short-awned, the awns to 2.5 mm.

Ecology: Found on dry, often rocky slopes and flats, often in open oak and juniper woodlands, from 2,500-5,500 ft (762-1676 m); flowers May-July.

Distribution: sw US, from se CA and NV east through AZ, UT, NM and CO to w TX, w OK, and w KS.

Notes: Look for low clusters of grass blades with tall naked flowering stalks topped with closely imbricate, (overlapping) short-awned spikelets. Tufts of hairs at the base of each floret are visible on close examination, the trait that gives this genus its common name, wolly grass.

Ethnobotany: Unknown

Etymology: Erioneuron is form Greek erion, wool and neuron, nerve, meaning woolly-nerved, while pilosum means woolly or hairy.

Synonyms: Tridens pilosus, Uralepis pilosa

Editor: SBuckley 2010, AHazelton 2015