Common names: Quackgrass Couchgrass Chiendent Chiendent rampant
Introduced
Synonyms: Aristata Elytrigia repens Agropyron repens var. vaillantianum Vaillantianum Agropyron repens var. typicum Trichorrhachis Agropyron repens var. subulatum Setiferum Agropyron repens var. pilosum Heberhachis Aristatum Agropyron repens
Treatment appears in FNA Volume 24. Treatment on page 334.

Plants strongly rhizomatous, sometimes glaucous. Culms 50-100 cm. Leaves 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. Spikes 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. Spikelets 10-27 mm, appressed to ascending, with 4-7 florets; disarticulation above the glumes, beneath each floret. Glumes 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. 2n = 22, 42.

Distribution

Conn., N.J., N.Y., Wash., Va., W.Va., Del., D.C., Wis., Idaho, Mont., Oreg., Wyo., Mass., Maine, N.H., R.I., Vt., N.Mex., Tex., N.C., Tenn., Pa., Calif., Nev., Colo., Alaska, Kans., N.Dak., Nebr., Okla., S.Dak., Ark., Ill., Ind., Iowa, Ariz., Alta., B.C., Greenland, Man., N.B., Nfld. and Labr., N.S., N.W.T., Nunavut, Ont., P.E.I., Que., Sask., Yukon, Md., Ohio, Utah, Mo., Minn., Mich., Miss., Ky.

Discussion

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.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Elymus repens"
pilose +  and glabrous +
membranous +  and scarious +
glabrous +  and pilose +
with hairs +  and scabrous +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
emarginate +  and awned +
Rounded (?) +, Truncate (?) +  and Acute (?) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
Mary E. Barkworth +, Julian J.N. Campbell +  and Bjorn Salomon +
(L.) Gould +
1 (?) +  and 3 (?) +
10 cm100 mm <br />0.1 m <br /> (?) +
straight +
basal +  and apical +
from the sinus +  and terminal +
not geniculate +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
not evident +
cross +, linear +  and narrowly lanceolate +
6mm;10mm +
spikelike +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
hairy +  and glabrous +
Quackgrass +, Couchgrass +, Chiendent +  and Chiendent rampant +
not branching +
sometimes strongly decumbent +  and prostrate +
usually erect +  and ascending +
50 cm500 mm <br />0.5 m <br /> (100 cm1,000 mm <br />1 m <br />) +
not woody +
Conn. +, N.J. +, N.Y. +, Wash. +, Va. +, W.Va. +, Del. +, D.C. +, Wis. +, Idaho +, Mont. +, Oreg. +, Wyo. +, Mass. +, Maine +, N.H. +, R.I. +, Vt. +, N.Mex. +, Tex. +, N.C. +, Tenn. +, Pa. +, Calif. +, Nev. +, Colo. +, Alaska +, Kans. +, N.Dak. +, Nebr. +, Okla. +, S.Dak. +, Ark. +, Ill. +, Ind. +, Iowa +, Ariz. +, Alta. +, B.C. +, Greenland +, Man. +, N.B. +, Nfld. and Labr. +, N.S. +, N.W.T. +, Nunavut +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Md. +, Ohio +, Utah +, Mo. +, Minn. +, Mich. +, Miss. +  and Ky. +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
4 +  and 7 +
laterally compressed +  and terete +
(0)1-7-veined +
shorter than to longer than the adjacent florets +
subtending +
keeled +  and oblong +
unequal +, subequal +  and reduced +
uncinate +
0 cm0 mm <br />0 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
solid +  and hollow +
1.5 cm15 mm <br />0.015 m <br /> (?) +
0.4 cm4 mm <br />0.004 m <br /> (?) +  and 0.6 cm6 mm <br />0.006 m <br /> (?) +
pilose +, puberulent +, glabrous +, scabrous +  and smooth +
0.2 cm2 mm <br />0.002 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (?) +  and 0.12 cm1.2 mm <br />0.0012 m <br /> (?) +
conspicuous +  and inconspicuous +
ciliate +  and scabrous +
distributed +
scabridulous +
linear-lanceolate +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
stiffly membranous +  and coriaceous +
erose +  and entire +
acute +, rounded +  and truncate +
0.025 cm0.25 mm <br />2.5e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
0.88 cm8.8 mm <br />0.0088 m <br /> (1.14 cm11.4 mm <br />0.0114 m <br />) +
concealed +  and prominent +
few +  and 2 +
2 +  and 1 +
hairy +  and glabrous +
well-developed +
slightly longer +
subequal +
0.7 cm7 mm <br />0.007 m <br /> (0.95 cm9.5 mm <br />0.0095 m <br />) +
dry +  and fleshy +
spikelike +
glabrous +  and pilose +
Introduced +
5 cm50 mm <br />0.05 m <br /> (?) +  and 15 cm150 mm <br />0.15 m <br /> (?) +
subsessile +  and sessile +
bisexual +  and sterile +
terete +  and compressed +
1 cm10 mm <br />0.01 m <br /> (2.7 cm27 mm <br />0.027 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
not papillate +
Aristata +, Elytrigia repens +, Agropyron repens var. vaillantianum +, Vaillantianum +, Agropyron repens var. typicum +, Trichorrhachis +, Agropyron repens var. subulatum +, Setiferum +, Agropyron repens var. pilosum +, Heberhachis +, Aristatum +  and Agropyron repens +
Elymus repens +
species +
membranous +
0 cm0 mm <br />0 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
inconspicuous +
unequal +
aquatic +  and terrestrial +