Elymus curvatus
Elymus repens
awnless wild-rye, awnless wlldrye, beardless wild rye
chiendent, chiendent rampant, couch grass, creeping wild-rye, quack grass, quackgrass wildrye
60-110 cm, stiffly erect, or the base sometimes geniculate;
nodes 6-9, concealed or exposed, glabrous.
50-100 cm.
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.
sometimes somewhat basally concentrated;
sheaths pilose or glabrous proximally;
auricles 0.3-1 mm;
ligules 0.25-1.5 mm;
blades 6-10 mm wide, usually flat, abaxial surfaces glabrous or sparsely pilose, adaxial surfaces usually sparsely pilose over the veins, sometimes glabrous, veins smooth, widely spaced, primary veins prominent, separated by the secondary veins.
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.
5-15 cm long, 0.5-1.5 cm wide, erect, usually with 1 spikelet per node, occasionally with 2 at a few nodes;
internodes 4-6(9.5) mm long, 0.5-1.2 mm wide, smooth or scabrous, glabrous, evenly puberulent, or sparsely pilose, hairs to 0.3 mm.
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.
10-27 mm, appressed to ascending, with 4-7 florets;
disarticulation above the glumes, beneath each floret.
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.
oblong, glabrous, keeled distally, keels inconspicuous and smooth proximally, scabrous and conspicuous distally, lateral veins inconspicuous, hyaline margins present in the distal 1/2, apices acute, unawned or awned, awns to 3 mm;
lower glumes 8.8-11.4 mm, 3-6-veined;
upper glumes 7-12 mm, 5-7-veined;
lemmas 8-12 mm, glabrous, mostly smooth, sometimes scabridulous distally, unawned or with a 0.2-4(10) mm awn, awns straight;
paleas 7-9.5 mm, keels ciliate from 1/2 to almost the entire length, apices emarginate, truncate, or rounded;
anthers 4-7 mm.
late June to mid-August.
= 28, 42.
= 22, 42.
Elymus curvatus
Elymus repens
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 repens is native to Eurasia; it is now established through much of the Flora region, extending from Alaska to Greenland and south to California, Texas, and North Carolina. It grows well in disturbed sites, spreading rapidly via its long rhizomes, as well as by seed. It is also drought tolerant. Although it is listed a noxious weed in several states, it provides good forage. It differs from E. hoffmannii (see next) in having widely spaced, unequally prominent leaf veins and, usually, shorter awns.
Godley (1947) demonstrated that lemma awn development, glaucousness, and the pubescence of the rachises are each effectively controlled by single genes. Long-awned plants are homozygous recessive, and awn-tipped plants homozygous dominant; glaucousness is dominant over non-glaucousness, and glabrous rachises over pubescent rachises. Awned plants appear to be established along the coasts of Newfoundland and Nova Scotia. They have generally been identified as Agropyron pungens (Pers.) Roem. & Schult., a species that has obtuse, mucronate lemmas.
Elymus repens is almost always a hexaploid. Most studies indicate that its genomic constitution is StStH, but Mason-Gamer (2001) demonstrated that it is genetically more complex than is implied by such a simple formula.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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