×elyleymus aristatus
Plants not or shortly rhizomatous. Culms 60-130 cm, glabrous. Leaves evenly distributed on the culms; sheaths smooth, glabrous; auricles poorly developed, to 0.5 mm; ligules 1-2.5 mm, scarious, rounded; blades about 5.5 mm wide, abaxial surfaces glabrous, mostly smooth, scabrous near the margins, adaxial surfaces scabridulous, primary-veins separated by about 3 secondary-veins. Inflorescences spikes, 6-15 cm long, 10-15 mm wide including the awns, 7-10 mm wide excluding the awns, erect, with 2-3 sessile or subsessile spikelets per node; internodes 4-7 mm, concealed by the spikelets; disarticulation tardy, in the rachises and beneath the florets. Spikelets 10-20 mm excluding the awns, to 18 mm including the awns, with 3-4 florets. Glumes 8-15 mm long, 0.3-0.5 mm wide, subequal to unequal, scabrous; lemmas 7.5-12 mm, glabrous, smooth or scabrous, sometimes only scabrous distally, midveins prominent and scabrous distally, awns 4-5 mm; anthers 2.2-2.4 mm.
Distribution
Colo., Wash., Calif., Oreg., Wyo., Idaho, Nev.
Discussion
Dewey and Holmgren (1962) argued that ×Elyleymus aristatus comprises hybrids between Elymus elymoides and Leymus cinereus or L. triticoides. It has been found at many locations where the parents are sympatric.
Selected References
None.
Lower Taxa
"decumbent" is not a number.