Eremopyrum

Plants annual. Culms 3-40 cm, geniculate. Sheaths open for most of their length; auricles present, often inconspicuous; ligules 0.4-2 mm, membranous, truncate; blades 1-6 mm wide, flat, linear. Inflorescences distichous spikes, 0.8-4.5 cm, with 1 spikelet per node, usually erect when mature; rachis internodes flat, margins glabrous or with hairs, hairs white; middle internodes 0.5-3 mm; disarticulation in the rachises, at the nodes beneath each spikelet, or at the base of each floret. Spikelets 6-25 mm, including the awns, more than 3 times the length of the internodes, divergent, laterally compressed, with 2-5 bisexual florets, sterile florets distal or absent. Glumes equal, 4-19 mm, including the awns, coriaceous, becoming indurate, 1-keeled initially, sometimes 2-keeled at maturity, keels glabrous or hairy, never with tufts of hair, bases slightly connate, apices tapering to a sharp point or straight awn; lemmas 5-24 mm, coriaceous, rounded basally, keeled distally, 5-veined, unawned or shortly awned; paleas usually shorter and thinner than the lemmas, 2-keeled, ciliate or scabrous distally, keels sometimes prolonged into 2 toothlike appendages; anthers 3, 0.4-1.3 mm, yellow. Ovaries pubescent; styles 2, free to the base, x = 7. Haplomes F, Xe.

Distribution

Colo., N.Mex., Wash., N.Y., Utah, Wyo., Nebr., Oreg., Mont., Alta., B.C., Man., Sask., Idaho, Ariz., Nev.

Discussion

Eremopyrum includes 5-10 species that grow in steppes and semidesert regions from Turkey to central Asia and Pakistan. Three species have been found in North America; only E. triticeum is widepsread. In their native ranges, species of Eremopyrum are valuable fodder on ephemeral spring pastures.

Selected References

Frederiksen, S. 1991. Taxonomic studies in Eremopyrum (Poaceae). Nordic J. Bot. 11:271-285

Melderis, A. 1985. Eremopyrum (Ledeb.) Jaub. & Spach. Pp. 227-231 in P.H. Davis (ed.). Flora of Turkey and the East Aegean Islands, vol. 9. University Press, Edinburgh, Scotland. 724 pp.

Sakamoto, S. 1979. Genetic relationships among four species of the genus Eremopyrum in the tribe Triticeae, Gramineae. Mem. Coll. Agric. Kyoto Univ. 114:1-27.

Lower Taxa

Eremopyrum bonaepartis, Eremopyrum orientale, Eremopyrum triticeum

Key

1	Glumes 1-veined and 2-keeled at maturity; lemmas of the first floret in each spikelet pubescent on the lower 1/2, glabrous distally, the other lemmas glabrous; disarticulation beneath the florets, sometimes at the base of the spikes	Eremopyrum triticeum
1	Glumes usually 3-5-veined and 1-keeled; lemmas of all florets alike in their pubescence or lack thereof; disarticulation at the rachis nodes.	> 2
2	Glume bases straight; spikes 1.3-2.8 cm wide	Eremopyrum bonaepartis
2	Glume bases arcuately curved; spikes 0.9-1.8 cm wide	Eremopyrum orientate