Treatment appears in FNA Volume 25. Treatment on page 44.

Plants perennial; usually cespitose, occasionally stoloniferous. Culms 6-65 cm, erect. Leaves mostly basal; sheaths smooth, glabrous, striate, margins hyaline, collars with tufts of 1-3 mm hairs; blades usually folded, pilose basally, margins white, cartilaginous, apices acute but not sharp. Inflorescences terminal, simple panicles (racemes in depauperate specimens), exserted well above the leaves. Spikelets laterally compressed, with 3-20 florets, distal florets staminate or sterile; disarticulation above the glumes and between the florets. Glumes thin, membranous, 1-veined, acute to acuminate; calluses with hairs; lemmas rounded on the back, 3-veined, veins conspicuously pilose, at least basally, apices toothed or obtusely 2-lobed, midveins often extended into awns, awns to 4 mm, lateral veins sometimes extended as small mucros; paleas shorter than the lemmas, keels ciliate, intercostal regions pilose basally; lodicules 2, adnate to the bases of the paleas; anthers 1 or 3. Caryopses glossy, translucent; embryos more than 1/2 as long as the caryopses. x = 8.


Kans., Okla., Colo., N.Mex., Tex., Utah, Calif., Ariz., Nev.


Erioneuron is an American genus of three species. Its seedlings appear to have a shaggy, white-villous indumentum, but this is composed of a myriad of small, water-soluble crystals.

Stoloniferous plants are unusual in the region covered by the Flora, but they are quite common in populations of Erioneuron nealley and E. avenaceum from central Mexico.


1 Lemmas entire or with teeth to 0.5 mm long, the awns 0.5-2.5 mm long; both glumes shorter than the lowest floret Erioneuron pilosum
1 Lemmas 2-lobed, the lobes 1-2.5 mm long, the awns 1-4 mm long; upper glumes equaling or exceeding the lowest floret. > 2
2 Lemma lobes obtuse to broadly acute, 1-2 mm long; lateral veins not forming mucros; plants 7-40 cm tall Erioneuron avenaceum
2 Lemma lobes rounded to truncate, 1.5-2.5 mm long; lateral veins forming mucros to 1 mm long; plants 15-65 cm tall Erioneuron nealleyi