The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

awnless wild-rye, awnless wlldrye, beardless wild rye

Arizona ryegrass, Arizona wheatgrass, Arizona wildrye

Habit Plants cespitose, not rhizomatous, often glaucous. Plants cespitose, not rhizomatous.
Culms

60-110 cm, stiffly erect, or the base sometimes geniculate;

nodes 6-9, concealed or exposed, glabrous.

45-100 cm, erect or decumbent at the base;

nodes glabrous or almost so.

Leaves

evenly distributed;

sheaths glabrous, often reddish brown;

auricles to 1 mm, sometimes absent;

ligules shorter than 1 mm, ciliolate;

blades 5-15 mm wide, the lower blades usually lax, shorter, narrower, and senescing earlier, the upper blades usually ascending and somewhat involute, adaxial surfaces smooth or scabridulous, occasionally scabrous.

evenly distributed over the lower 1/2 of the culms;

sheaths glabrous;

auricles usually present, to 1 mm;

ligules to 1 mm on the basal leaves, 1-3 mm on the flag leaves;

blades 2.5-6 mm wide, lax, abaxial surfaces smooth and glabrous, adaxial surfaces scabrous, with scattered 0.5-1 mm hairs, veins close together.

Spikes

9-15 cm long, (0.5)0.7-1.3 cm wide, erect, exserted or the bases slightly sheathed, with 2 spikelets per node;

internodes 2.5-4.5 mm long, about 0.25-5 mm thick at the thinnest sections, smooth or scabrous beneath the spikelets.

12-25 cm long, 2.5-6 cm wide including the awns, 10-15 mm wide excluding the awns, flexuous, usually nodding or pendent at maturity, with 1 spikelet per node;

internodes 11-17 mm long, 0.4-1 mm wide, glabrous, mostly smooth, scabrous on the edges.

Spikelets

10-15 mm, appressed, often reddish brown at maturity, with (2)3-4(5) florets, lowest florets functional;

disarticulation below the glumes and beneath the florets, or the lowest floret falling with the glumes.

14-26 mm long, 6-8 mm wide, appressed to divergent, 1.5-2 times as long as the internodes, with 4-6 florets;

rachillas glabrous;

disarticulation above the glumes and beneath each floret.

Glumes

equal or subequal, the basal 2-3 mm terete, indurate, strongly bowed out, without evident venation, glume bodies 7-15 mm long, 1.2-2.1 mm wide, linear-lanceolate, widening above the base, 3-5-veined, usually glabrous or scabrous, occasionally hispidulous, rarely hirsute on the veins, margins firm, awns 0-3(5) mm;

lemmas 6-10 mm, glabrous or scabrous, rarely hirsute, awns (0.5)1-3(4) mm, rarely 5-10 mm on the lemmas of the distal spikelets, straight;

paleas 6-10 mm, obtuse, often emarginate;

anthers 1.5-3 mm.

narrowly lanceolate, margins about 0.2 mm wide, 3(5)-veined, the bases flat, evidently veined, margins hyaline, widest at about midlength, acute or acuminate, unawned or awned, awns to 4 mm, straight;

lower glumes 5-9 mm;

upper glumes 8-10 mm;

lemmas 8-15 mm, scabrous, rounded on the back, awns 10-25 mm, arcuately diverging;

paleas as long as or longer than the lemmas, tapering, apices truncate, about 0.3 mm wide;

anthers 3-5 mm.

Anthesis

late June to mid-August.

2n

= 28, 42.

= 28.

Elymus curvatus

Elymus arizonicus

Distribution
from USDA
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; NM; TX
[WildflowerSearch map]
[BONAP county map]
Discussion

Elymus curvatus grows in moist or damp soils of open forests, thickets, grasslands, ditches, and disturbed ground, especially on bottomland. It is widespread from British Columbia and Washington, through the Intermountain region and northern Rockies, to the northern Great Plains. It is infrequent or rare in the midwest, the Great Lakes region, and the northeast, and is virtually unknown in the southeast. It is similar to E. virginicus (p. 298), and has sometimes been included in that species as E. virginicus var. submuticus Hook., but is more distinct than the varieties of E. virginicus treated above. Although E. virginicus and E. curvatus overlap greatly in range, E. curvatus usually has a distinct growth form, and its anthesis is 1-2 weeks later (Brooks 1974). Its spikes range from being completely exserted, especially west of the Great Plains, to largely sheathed, especially east of the Mississippi River and in more stressed environments. This geographic trend parallels that within E. virginicus, but sheathed plants of E. curvatus can usually be distinguished by their short awns. Clear transitions to E. virginicus, usually var. jejunus, are rare, but, especially from Missouri to Wisconsin, there are occasional plants with 5-10 mm awns on a few lemmas, especially at the spike tips. Rarely, plants from Missouri and Iowa to Quebec have hispid to hirsute spikelets, suggesting introgression with E. virginicus var. intermedius. There are a few records of apparent hybrids with other species.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Elymus arizonicus grows in moist, rocky soil in mountain canyons of the southwestern United States and northern Mexico. When mature, the drooping spike and solitary spikelets make E. arizonicus easy to identify. Immature specimens, or those mounted so that the spike appears erect, are easily mistaken for Pseudoroegneria spicata (p. 281), but they have thicker culms and longer ligules, more basal leaves, and wider leaf blades.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 24, p. 300. FNA vol. 24, p. 329.
Parent taxa Poaceae > subfam. Pooideae > tribe Triticeae > Elymus Poaceae > subfam. Pooideae > tribe Triticeae > Elymus
Sibling taxa
E. alaskanus, E. albicans, E. arizonicus, E. bakeri, E. canadensis, E. caninus, E. churchii, E. ciliaris, E. dahuricus, E. diversiglumis, E. elymoides, E. glabriflorus, E. glaucus, E. hirsutus, E. hoffmannii, E. hystrix, E. interruptus, E. lanceolatus, E. macgregorii, E. macrourus, E. multisetus, E. pringlei, E. repens, E. riparius, E. scribneri, E. semicostatus, E. sibiricus, E. sierrae, E. stebbinsii, E. svensonii, E. texensis, E. trachycaulus, E. tsukushiensis, E. villosus, E. violaceus, E. virginicus, E. wawawaiensis, E. wiegandii, E. ×cayouetteorum, E. ×ebingeri, E. ×hansenii, E. ×palmerensis, E. ×pinalenoensis, E. ×pseudorepens, E. ×saundersii, E. ×yukonensis
E. alaskanus, E. albicans, E. bakeri, E. canadensis, E. caninus, E. churchii, E. ciliaris, E. curvatus, E. dahuricus, E. diversiglumis, E. elymoides, E. glabriflorus, E. glaucus, E. hirsutus, E. hoffmannii, E. hystrix, E. interruptus, E. lanceolatus, E. macgregorii, E. macrourus, E. multisetus, E. pringlei, E. repens, E. riparius, E. scribneri, E. semicostatus, E. sibiricus, E. sierrae, E. stebbinsii, E. svensonii, E. texensis, E. trachycaulus, E. tsukushiensis, E. villosus, E. violaceus, E. virginicus, E. wawawaiensis, E. wiegandii, E. ×cayouetteorum, E. ×ebingeri, E. ×hansenii, E. ×palmerensis, E. ×pinalenoensis, E. ×pseudorepens, E. ×saundersii, E. ×yukonensis
Synonyms E. virginicus var. submuticus, E. virginicus var. jenkinsii, E. submuticus Pseudoroegneria arizonica, Agropyron arizonicum
Name authority Piper (Scribn. & J.G. Sm.) Gould
Web links