Erioneuron

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.

Distribution

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

Discussion

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.

Selected References

Sanchez, E. 1979. Anatomia foliar de las especies y variedades argentinas de los generos Tridens Roem. et Schult. y Erioneuron Nash (Gramineae-Eragrostoideae-Eragrosteae). Darwiniana 22:159-175

Valdes-Reyna, J. and S.L. Hatch. 1997. A revision of Erioneuron and Dasyochloa (Poaceae: Eragrostideae). Sida 17:645-666.

Lower Taxa

Erioneuron avenaceum, Erioneuron nealleyi, Erioneuron pilosum

Key

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