View source for Elymus

{{Treatment/ID
|accepted_name=Elymus
|accepted_authority=L.
|publications=
|basionyms=
|synonyms=
|hierarchy=Poaceae;Poaceae subfam. Pooideae;Poaceae tribe Triticeae;Elymus
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Poaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Poaceae subfam. Pooideae]]</div><div class="higher-taxon"><small>tribe</small>[[Poaceae tribe Triticeae]]</div><div class="higher-taxon"><small>genus</small>[[Elymus]]</div></div>
|volume=Volume 24
|mention_page=
|treatment_page=page 288
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Plants </b>perennial; sometimes cespitose, sometimes rhizomatous, sometimes stoloniferous. <b>Culms</b> 8-180(220) cm, usually erect to ascending, sometimes strongly decumbent to prostrate, usually glabrous. <b>Leaves</b> usually evenly distributed, sometimes somewhat basally concentrated; sheaths open for most of their length; auricles often present; ligules membranous, usually truncate or rounded, sometimes acute, entire or erose, often ciliolate; blades 1-24(25) mm wide, abaxial surfaces usually smooth or scabrous, sometimes with hairs, adaxial surfaces scabrous or with hairs, particularly over the veins, usually with unequal, not strongly ribbed, widely spaced veins, sometimes with equal, strongly ribbed, closely spaced veins. <b>Inflorescences</b> spikes, usually exserted, with 1-3(5) spikelets per node, internodes (1.5)2-26 mm; rachises with scabridulous, scabrous, or ciliate edges. <b>Spikelets</b> usually appressed to ascending, sometimes strongly divergent or patent, with 1-11 florets, the lowest florets usually functional, sterile and glumelike in some species, the distal florets often reduced; disarticulation usually above the glumes and beneath each floret, sometimes also below the glumes or in the rachises. <b>Glumes</b> usually 2, absent or highly reduced in some species, usually equal to subequal, sometimes unequal, usually linear-lanceolate to linear, setaceous, or subulate, sometimes oblanceolate to obovate, (0)1-7-veined, sometimes keeled over 1 vein, not necessarily the central vein, keel vein sometimes extending into an awn; lemmas linear-lanceolate, obscurely 5(7)-veined, apices acute, often awned, sometimes bidentate, teeth to 0.2 mm, sometimes with bristles, bristles to 10 mm, awns terminal or from the sinus, straight or arcuately divergent, not geniculate; paleas from shorter than to slightly longer than the lemmas, keels scabrous or ciliate, at least in part; anthers 3, 0.7-7 mm. <b>Caryopses</b> with hairy apices, x = 7. <b>Haplomes</b> St, H, Y, P.</span><!--

-->{{Treatment/Body
|distribution=Idaho;Mont.;Nebr.;N.C.;Conn.;N.J.;N.Y.;Mass.;Wash.;Va.;W.Va.;Ark.;Iowa;Kans.;Mo.;N.Dak.;Okla.;S.Dak.;Ariz.;D.C;Ga.;Ill.;Ky.;Mich.;N.Mex.;Pa.;S.C.;Tenn.;Wyo.;Del.;Miss.;Ind.;Oreg.;Maine;N.H.;R.I.;Vt.;Ala.;Fla.;La.;Md.;N.S.;Ohio;Tex.;Wis.;Colo.;Calif.;Alaska;Utah;Nev.;Alta.;B.C.;Greenland;Man.;N.B.;Nfld. And Labr.;N.W.T.;Nunavut;Ont.;P.E.I.;Que.;Sask.;Yukon;Minn.
|discussion=<p>Name from the Greek elyo, 'rolled up', the caryopses being tightly embraced by the lemma and palea.</p><!--
--><p>All species of <i>Elymus</i> are alloploids that combine one copy of the St haplome present in <i>Pseudoroegneria</i> with at least one other haplome. So far as is known, all species that are native to North America, as well as many species native to northern Eurasia, are tetraploids with one additional haplome, the H genome from <i>Hordeum</i> sect. Critesion. Many Asian species combine the St haplome with the Y haplome, for which there are no known diploids; such species are sometimes placed in the segregate genus Roegneria. This treatment includes two such species, <i>E. ciliaris</i> and <i>E. semicostatus</i>. In addition, the treatment includes two hexaploid species, E. tsukusbiensis and <i>E. dahuricus</i>, that combine all three haplomes. <i>Elymus repens</i> and <i>E. hoffmannii</i>, the other two hexaploid species in this treatment, basically combine two copies of the St haplome with one of the H haplome, but the molecular data for <i>E. repens</i> point to a more complex situation (Mason-Gamer 2001). For further discussion of generic delimitation in the Triticeae, see Barkworth (2000), Yen et al. (2005), and Barkworth and von Bothmer (2005).</p><!--
--><p><i>Elymus</i> is sometimes divided into multiple sections (see, for example, Tsvelev 1976; Love 1984). There are, however, no detailed morphological descriptions of the sections, making it difficult to determine how to treat the North American species. It is notable that the species with solitary spikelets are concentrated in western and northern North America, whereas the species with multiple spikelets at a node are most prevalent east of the Rocky Mountains, from southern Canada to the Gulf Coast. There are exceptions to this statement. For instance, species with multiple spikelets and disarticulating rachises are primarily western in their distribution, yet <i>E. glaucus</i>, a species with multiple spikelets and non-disarticulating rachises, is western. Like the western species with solitary spikelets, and unlike most eastern species, its glumes have a hyaline margin.</p>
|tables=
|references={{Treatment/Reference
|id=barkworth1997a
|text=Barkworth, M.E. 1997. Taxonomic and nomenclatural comments on the Triticeae in North America. Phytologia 83:302-311
}}{{Treatment/Reference
|id=barkworth2000a
|text=Barkworth, M.E. 2000. Changing perceptions in the Triticeae. Pp. 110-120 in S.W.L. Jacobs and J. Everett (eds.). Grasses: Systematics and Evolution. CSIRO Publishing, Collingwood, Victoria, Australia. 408 pp.
}}{{Treatment/Reference
|id=barkworth2005a
|text=Barkworth, M.E. and R. von Bothmer. 2005. Twenty-one years later: Love and Dewey's genomic classification proposal. Czech J. Genet. PI. Breed. 41 (Special Issue): 3-9
}}{{Treatment/Reference
|id=bennett2006a
|text=Bennett, B.A. 2006. Siberian Wild Rye (Elymus sibiricus L., Poaceae) in western North America: Native or introduced? BEN [Botanical Electronic News] #366. http://wvw.ou.edu/cas/botany-micro/ben/
}}{{Treatment/Reference
|id=bodvarsdottir2003a
|text=Bodvarsdottir, S.K. and K. Anamthawat-Jonsson. 2003. Isolation, characterization, and analysis of Leymus-specidc DNA sequences. Genome 46:673-682
}}{{Treatment/Reference
|id=booher1948a
|text=Booher, L.E. and R.M. Tryon. 1948. A study of Elymus in Minnesota. Rhodora 50:80-91
}}{{Treatment/Reference
|id=bowden1958a
|text=Bowden, W.M. 1958. Natural and artificial ×Elymordeum hybrids. Canad. J. Bot. 36:101-123
}}{{Treatment/Reference
|id=bowden1964a
|text=Bowden, W.M. 1964. Cytotaxonomy of the species and interspecific hybrids of the genus Elymus in Canada and neighboring areas. Canad. J. Bot. 42:547-601
}}{{Treatment/Reference
|id=bowden1967a
|text=Bowden, W.M. 1967. Taxonomy of intergeneric hybrids of the tribe Triticeae from North America. Canad. J. Bot. 45:711-724
}}{{Treatment/Reference
|id=brooks1974a
|text=Brooks, R.E. 1974. Intraspecific variation in Elymus virginicus (Gramineae) in the central United States. Master's thesis, University of Kansas, Lawrence, Kansas, U.S.A. 112 pp.
}}{{Treatment/Reference
|id=brown1960a
|text=Brown, W.V. and G.A. Pratt. 1960. Hybridization and introgression in the genus Elymus. Amer. J. Bot. 47:669-676
}}{{Treatment/Reference
|id=bush1926a
|text=Bush, B.F. 1926. The Missouri species of Elymus. Amer. Midi. Naturalist 10:49-88
}}{{Treatment/Reference
|id=campbell2000a
|text=Campbell, J.J.N. 2000. Notes on North American Elymus species (Poaceae) with paired spikelets: I. E. macgregorii sp. nov. and E. glaucus ssp. mackenzii comb. nov. J. Kentucky Acad. Sci. 61:88-98
}}{{Treatment/Reference
|id=campbell2002a
|text=Campbell, J.J.N. 2002. Notes on North American Elymus species (Poaceae) with paired spikelets: II. The interruptus group. J. Kentucky Acad. Sci. 62:19-38
}}{{Treatment/Reference
|id=campbell2002b
|text=Campbell, J.J.N. and A. Haines. 2002. Corrections and additions to: Campbell, J.J.N. 2000. Notes on North American Elymus species (Poaceae) with paired spikelets: I. E. macgregorii sp. nov. and E. glaucus ssp. mackenzii comb. nov. J. Ky. Acad. Sci. 61:88-98. J. Kentucky Acad. Sci. 62:65
}}{{Treatment/Reference
|id=church1954a
|text=Church, G.L. 1954. Interspecific hybridization in eastern Elymus. Rhodora 56:185-197
}}{{Treatment/Reference
|id=church1958a
|text=Church, G.L. 1958. Artificial hybrids of Elymus virginicus with E. canadensis, E. interruptus, E. riparius, and E. wiegandii. Amer. J. Bot. 45:410-417
}}{{Treatment/Reference
|id=church1967a
|text=Church, G.L. 1967a. Taxonomic and genetic relationships of eastern North American species of Elymus with setaceous glumes. Rhodora 69:121-162
}}{{Treatment/Reference
|id=church1967b
|text=Church, G.L. 1967b. Pine Hills Elymus. Rhodora 69:330-345
}}{{Treatment/Reference
|id=davies1980a
|text=Davies, R.S. 1980. Introgression between Elymus canadensis and E. virginicus L. (Triticeae, Poaceae) in south central United States. Ph.D. dissertation, Texas A&M University, College Station, Texas, U.S.A. 232 pp.
}}{{Treatment/Reference
|id=dewey1963a
|text=Dewey, D.R. 1963. Natural hybrids of Agropyron trachycaulutn and Agropyron scribneri. Bull. Torrey Bot. Club 90:111-120
}}{{Treatment/Reference
|id=dewey1965a
|text=Dewey, D.R. 1965. Morphology, cytology, and fertility of synthetic hybrids of Agropyron spicatum x Agropyron dasystachyum-riparium. Bot. Gaz. 126:269-275
}}{{Treatment/Reference
|id=dewey1967a
|text=Dewey, D.R. 1967a. Genome relations between Agropyron scribneri and Sitanion bystrix. Bull. Torrey Bot. Club 94:395-404
}}{{Treatment/Reference
|id=dewey1967b
|text=Dewey, D.R. 1967b. Synthetic Agropyron-Elymus hybrids: II. Elymus canadensis x Agropyron dasystachutn. Amer. J. Bot. 54:1084-1089
}}{{Treatment/Reference
|id=dewey1968a
|text=Dewey, D.R. 1968. Synthetic hybrids of Agropyron dasystachyum x Elymus glaucus and Sitanion bystrix. Bot. Gaz. 129:316-322
}}{{Treatment/Reference
|id=dewey1970a
|text=Dewey, D.R. 1970. The origin of Agropyron albicans. Amer. J. Bot. 57:12-18
}}{{Treatment/Reference
|id=dewey1974a
|text=Dewey, D.R. 1974. Cytogenetics of Elymus sibiricus and its hybrids with Agropyron tauri, Elymus canadensis, and Agropyron caninum. Bot. Gaz. 135:80-87
}}{{Treatment/Reference
|id=dewey1975a
|text=Dewey, D.R. 1975. Introgression between Agropyron dasystachyum and A. trachycaulum. Bot. Gaz. 136:122-128
}}{{Treatment/Reference
|id=dewey1976a
|text=Dewey, D.R. 1976. Cytogenetics of Agropyron pringlei and its hybrids with A. spicatum, A. scribneri, A. violaceum, and A. dasystachyum. Bot. Gaz. 137:179-185
}}{{Treatment/Reference
|id=dewey1982a
|text=Dewey, D.R. 1982. Genomic and phylogenetic relationships among North American perennial Triticeae. Pp. 51-58 in J.R. Estes, R.J. Tyrl, and J.N. Brunken (eds.). Grasses and Grasslands. University of Oklahoma Press, Norman, Oklahoma, U.S.A. 312 pp.
}}{{Treatment/Reference
|id=gabel1984a
|text=Gabel, MX. 1984. A biosystematic study of the genus Elymus (Gramineae: Triticeae). Proc. Iowa Acad. Sci. 91:140-146
}}{{Treatment/Reference
|id=gillett1960a
|text=Gillett, J.M. and H.A. Senn. 1960. Cytotaxonomy and infraspecific variation of Agropyron smithii Rydb. Canad. J. Bot. 38:747-760
}}{{Treatment/Reference
|id=gillett1961a
|text=Gillett, J.M. and H.A. Senn. 1961. A new species of Agropyron from the Great Lakes. Canad. J. Bot. 39:1169-1175
}}{{Treatment/Reference
|id=godley1947a
|text=Godley, E.J. 1947. The variation and cytology of the British species of Agropyron and their natural hybrids. Master's thesis, Trinity College, Cambridge, England. 152 pp.
}}{{Treatment/Reference
|id=hitchcock1935a
|text=Hitchcock, A.S. 1935. Manual of the Grasses of the United States. U.S. Government Printing Office, Washington, D.C., U.S.A. 1040 pp.
}}{{Treatment/Reference
|id=hitchcock1951a
|text=Hitchcock, A.S. 1951. Manual of the Grasses of the United States, ed. 2, rev. A. Chase. U.S.D.A. Miscellaneous Publication No. 200. U.S. Government Printing Office, Washington, D.C., U.S.A. 1051 pp.
}}{{Treatment/Reference
|id=hitchcock1969d
|text=Hitchcock, C.L., A. Cronquist, and M. Ownbey. 1969. Vascular Plants of the Pacific Northwest, Vol. 1: Vascular Cryptogams, Gymnosperms, and Monocotyledons. University of Washington Press, Seattle, Washington, U.S.A. 914 pp.
}}{{Treatment/Reference
|id=hulten1968a
|text=Hulten, E. 1968. Flora of Alaska and Neighboring Territories. Stanford University Press, Stanford, California, U.S.A. 1008 pp.
}}{{Treatment/Reference
|id=jensen-a
|text=Jensen, K.B. and K.H. Asay. Cytology and morphology of Elymus hoffmannii (Poaceae: Triticeae): A new species from the Erzurum Province of Turkey. Int. J. PL Sci. 157:750-758
}}{{Treatment/Reference
|id=jensen1993a
|text=Jensen, K.B. 1993. Elymus magellanicus and its intra- and intergeneric hybrids with Pseudoroegneria spicata, Hordeum violaceum, E. trachycaulus, E. lanceolatus, and E. glaucus (Poaceae: Triticeae). Genome 36:72-76
}}{{Treatment/Reference
|id=jones1988b
|text=Jones, S.B., Jr. and N.C. Coile. 1988. The Distribution of the Vascular Flora of Georgia. University of Georgia, Athens, Georgia, U.S.A. 230 pp.
}}{{Treatment/Reference
|id=jozwik1966a
|text=Jozwik, EX. 1966. A biosystematic analysis of the slender wheatgrass complex. Ph.D. dissertation, University of Wyoming, Laramie, Wyoming, U.S.A. 112 pp.
}}{{Treatment/Reference
|id=lepage1952a
|text=Lepage, E. 1952. Études sur quelques plantes americaines: II. Hybrides intergeneriques Agrohordeum et Agroelymus. Naturaliste Canad. 79:241-266
}}{{Treatment/Reference
|id=lepage1965a
|text=Lepage, E. 1965. Revision genealogique de quelques xAgroelymus. Naturaliste Canad. 92:205-216
}}{{Treatment/Reference
|id=love1984a
|text=Love, A. 1984. Conspectus of the Triticeae. Feddes Repert. 95:425-521
}}{{Treatment/Reference
|id=mason-gamer2001a
|text=Mason-Gamer, R.J. 2001. Origin of North American Elymus (Poaceae: Triticeae) allotetraploids based on granule-bound starch synthase gene sequences. Syst. Bot. 26:757-768
}}{{Treatment/Reference
|id=nelson1978a
|text=Nelson, E.N. and R.J. Tyrl. 1978. Hybridization and introgression between Elymus canadensis and Elymus virginicus. Proc. Oklahoma Acad. Sci. 58:32-34
}}{{Treatment/Reference
|id=pohl1959a
|text=Pohl, R.W. 1959. Morphology and cytology of some hybrids between Elymus canadensis and E. virginicus. Proc. Iowa Acad. Sci. 66:155-159
}}{{Treatment/Reference
|id=pohl1966a
|text=Pohl, R.W. 1966. ×Elyhordeum iowense, a new intergeneric hybrid in the Triticeae. Brittonia 18:250-255
}}{{Treatment/Reference
|id=porsild1980a
|text=Porsild, A.E. and W.J. Cody. 1980. Vascular Plants of the Continental Northwest Territories, Canada. National Museum of Natural Sciences, National Museums of Canada, Ottawa, Ontario, Canada. 667 pp.
}}{{Treatment/Reference
|id=pyrah1983a
|text=Pyrah, G.L. 1983. Agropyron arizonicum (Gramineae: Triticeae) and a natural hybrid from Arizona. Great Basin Naturalist 43:131-135
}}{{Treatment/Reference
|id=salomon1991a
|text=Salomon, B., R. von Bothmer, and N. Jacobsen. 1991. Intergeneric crosses between Hordeum and North American Elymus (Poaceae: Triticeae). Hereditas 114:117-122
}}{{Treatment/Reference
|id=sanders1979a
|text=Sanders, T.S., J.L. Hamrick, and L.R. Holden. 1979. Allozyme variation in Elymus canadensis from the tallgrass prairie region: Geographic variation. Amer. Midi. Naturalist 101:1-12
}}{{Treatment/Reference
|id=smith1991a
|text=Smith, E.B. (ed.). 1991. An Atlas and Annotated List of the Vascular Plants of Arkansas, ed. 2. Edwin B. Smith, Fayetteville, Arkansas, U.S.A. 489 pp.
}}{{Treatment/Reference
|id=snyder1950a
|text=Snyder, L.A. 1950. Morphological variability and hybrid development in Elymus glaucus. Amer. J. Bot. 37:628-636
}}{{Treatment/Reference
|id=snyder1951a
|text=Snyder, L.A. 1951. Cytology of inter-strain hybrids and the probable origin of variability in Elymus glaucus. Amer. J. Bot. 38:195-202
}}{{Treatment/Reference
|id=stebbins1956a
|text=Stebbins, G.L., Jr. and L.A. Snyder. 1956. Artificial and natural hybrids in the Gramineae, tribe Hordeae: IX. Hybrids between the western and eastern species. Amer. J. Bot. 43:305-312
}}{{Treatment/Reference
|id=stebbins1957a
|text=Stebbins, G.L., Jr. 1957. The hybrid origin of microspecies in the Elymus glaucus complex. Pp. 336-340 in International Union of Biological Sciences (eds.). Proceedings of the International Genetics Symposia, 1956: Tokyo & Kyoto, September 1956. Organizing Committee, International Genetics Symposia, Science Council of Japan, Tokyo, Japan. 680 pp.
}}{{Treatment/Reference
|id=steyermark1963b
|text=Steyermark, J.A. 1963. Flora of Missouri. Iowa State University Press, Ames, Iowa, U.S.A. 1725 pp.
}}{{Treatment/Reference
|id=sun1998a
|text=Sun, G.-L., B. Salomon, and R. von Bothmer. 1998. Characterization of microsatellite loci from Elymus alaskanus and length polymorphism in several Elymus species (Triticeae: Poaceae). Genome 41:455-463
}}{{Treatment/Reference
|id=sun2003a
|text=Sun, G.-L. and B. Salomon. 2003. Microsatellite variability and heterozygote deficiency in the arctic-alpine Alaskan wheatgrass (Elymus alaskanus) complex. Genome 46:729-737
}}{{Treatment/Reference
|id=sun2006a
|text=Sun, G.L., H. Tang, and B. Salomon. 2006. Molecular diversity and relationships of North American Elymus trachycaulus and the Eurasian E. caninus species. Genetica 127:55-64
}}{{Treatment/Reference
|id=svitashev1998a
|text=Svitashev, S., T. Bryngelsson, X. Li, and R.R.-C. Wang. 1998. Genome-specific repetitive DNA and RAPD markers for genome identification in Elymus and Hordelymus. Genome 41:120-128
}}{{Treatment/Reference
|id=tsvelev1976a
|text=Tsvelev, N.N. 1976. Zlaki SSSR. Nauka, Leningrad [St. Petersburg], Russia. 788 pp.
}}{{Treatment/Reference
|id=vilkomerson1950a
|text=Vilkomerson, H. 1950. The unusual meiotic behavior of Elymus wiegandii. Exp. Cell Res. 1:534-542
}}{{Treatment/Reference
|id=wilson1963a
|text=Wilson, F.D. 1963. Revision of Sitanion (Triticeae, Gramineae). Brittonia 15:303-323
}}{{Treatment/Reference
|id=wilson2001a
|text=Wilson, B.L., J. Kitzmiller, W. Rolle, and V.D. Hipkins. 2001. Isozyme variation and its environmental correlates in Elymus glaucus from the California floristic province. Canad. J. Bot. 79:139-153
}}{{Treatment/Reference
|id=yen2005b
|text=Yen, C, J.-L. Yang, and Y. Yen. 2005. Hitoshi Kihara, Askell Love and the modern genetic concept of the genera in the tribe Triticeae (Poaceae). Acta Phytotax. Sin. 43:82-93
}}{{Treatment/Reference
|id=zhang2002b
|text=Zhang, X-Q., B. Salomon, and R. von Bothmer. 2002. Application of random amplified polymorphic DNA markers to evaluate intraspecific genetic variation in the Elymus alaskanus complex (Poaceae). Genet. Resources & Crop Evol. 49:397-407.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Spikelets 1 at all or most nodes; glumes with flat, non-indurate bases, glume bodies linear-lanceolate to obovate, margins hyaline, scarious, or chartaceous; lemmas awned or unawned [for opposite lead, see p. 292].
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Anthers 3-7 mm long; plants often strongly rhizomatous, sometimes not or only weakly rhizomatous.
|[[#key-0-3| > 3]]
|-id=key-0-3
|3
|At least some lemmas with strongly divergent, outcurving, or recurved awns.
|[[#key-0-4| > 4]]
|-id=key-0-4
|4
|Culms prostrate to decumbent and geniculate, 20-50 cm tall; plants of subalpine and alpine habitats
|[[Elymus sierrae|Elymus sierrae]]
|-id=key-0-4
|4
|Culms erect or decumbent only at the base, (15)40-130 cm tall; plants of valley and montane, but not subalpine or alpine, habitats.
|[[#key-0-5| > 5]]
|-id=key-0-5
|5
|Plants strongly rhizomatous; blades 1-3 mm wide
|[[Elymus albicans|Elymus albicans]]
|-id=key-0-5
|5
|Plants cespitose or weakly rhizomatous; blades 1.5-6 mm wide.
|[[#key-0-6| > 6]]
|-id=key-0-6
|6
|Spikes often drooping to pendent at maturity; rachis internodes 11-17 mm long; plants of the southwestern United States
|[[Elymus arizonicus|Elymus arizonicus]]
|-id=key-0-6
|6
|Spikes erect to slightly nodding at maturity; rachis internodes 5-12 mm long; plants of the northwestern contiguous United States
|[[Elymus wawawaiensis|Elymus wawawaiensis]]
|-id=key-0-3
|3
|Lemmas unawned or with straight to flexuous awns.
|[[#key-0-4| > 4]]
|-id=key-0-7
|7
|Lemmas 12-14 mm long; plants not or weakly rhizomatous.
|[[#key-0-8| > 8]]
|-id=key-0-8
|8
|Palea keels straight or slightly outwardly curved below the apices, apices about 0.2 mm wide between the vein ends
|[[Elymus glaucus|Elymus glaucus]]
|-id=key-0-8
|8
|Palea keels distinctly outwardly curved below the apices; apices 0.3-0.7 mm wide between the vein ends
|[[Elymus semicostatus|Elymus semicostatus]]
|-id=key-0-7
|7
|Lemmas 7-12 mm long; plants not, weakly, or strongly rhizomatous.
|[[#key-0-8| > 8]]
|-id=key-0-9
|9
|Glumes keeled distally, keels smooth and inconspicuous proximally, scabrous and conspicuous distally; lemmas glabrous.
|[[#key-0-10| > 10]]
|-id=key-0-10
|10
|Adaxial surfaces of the blades usually sparsely pilose, sometimes glabrous, veins smooth, the primary veins separated by secondary veins; plants strongly rhizomatous
|[[Elymus repens|Elymus repens]]
|-id=key-0-10
|10
|Adaxial surfaces of the blades glabrous, veins smooth or scabrous, all veins more or less equally prominent; plants slightly to moderately rhizomatous
|[[Elymus hoffmannii|Elymus hoffmannii]]
|-id=key-0-9
|9
|Glumes not keeled or keeled throughout their length, keels smooth or scabrous throughout, sometimes hairy, conspicuous or not; lemmas glabrous or hairy.
|[[#key-0-10| > 10]]
|-id=key-0-11
|11
|Plants strongly rhizomatous; glumes 5-9 mm long; lemmas densely to sparsely hairy or glabrous
|[[Elymus lanceolatus|Elymus lanceolatus]]
|-id=key-0-11
|11
|Plants cespitose or weakly rhizomatous; glumes 6-19 mm long; lemmas glabrous or pubescent, never densely hairy.
|[[#key-0-12| > 12]]
|-id=key-0-12
|12
|Spikelets usually at least twice as long as the internodes; internodes 4-12 mm long; glumes often awned, sometimes unawned; blades usually lax
|[[Elymus glaucus|Elymus glaucus]]
|-id=key-0-12
|12
|Spikelets from shorter than to almost twice as long as the internodes; internodes 9-27 mm long; glumes unawned; blades usually straight
|[[Elymus stebbinsii|Elymus stebbinsii]]
|-id=key-0-2
|2
|Anthers 0.7-3 mm long; plants usually not or weakly rhizomatous, sometimes strongly rhizomatous.
|[[#key-0-3| > 3]]
|-id=key-0-13
|13
|Culms prostrate or strongly decumbent at the base; disarticulation in the rachises or beneath the florets; plants of subalpine, alpine, and arctic habitats.
|[[#key-0-14| > 14]]
|-id=key-0-14
|14
|Glumes unawned or with awns to 1 mm long; plants of arctic habitats
|[[Elymus alaskanus|Elymus alaskanus]]
|-id=key-0-14
|14
|Glumes awned, awns 3-30 mm long; plants of subalpine and alpine habitats.
|[[#key-0-15| > 15]]
|-id=key-0-15
|15
|Anthers 1-1.6 mm long; internodes 2.5-5(7) mm long; disarticulation initially in the rachises; spikelets appressed to ascending
|[[Elymus scribneri|Elymus scribneri]]
|-id=key-0-15
|15
|Anthers 2-3.5 mm long; internodes 5-15 mm long; rachises not disarticulating; spikelets ascending to divergent
|[[Elymus sierrae|Elymus sierrae]]
|-id=key-0-13
|13
|Culms usually ascending to erect, sometimes geniculate or weakly decumbent at the base; disarticulation beneath the florets; plants of sea level to subalpine habitats.
|[[#key-0-14| > 14]]
|-id=key-0-16
|16
|Lemmas with coarse, stiff, marginal hairs up to 1 mm long; paleas 2/3 – 4/5 as long as the lemmas, with wide, rounded apices
|[[Elymus ciliaris|Elymus ciliaris]]
|-id=key-0-16
|16
|Lemmas with the marginal hairs, if present, similar to those elsewhere on the lemma; paleas 3/4 as long as to slightly longer than the lemmas, tapering to the apices.
|[[#key-0-17| > 17]]
|-id=key-0-17
|17
|Lemmas awned, awns 7-40 mm long.
|[[#key-0-18| > 18]]
|-id=key-0-18
|18
|Lemma awns strongly arcuate to outcurving or recurved.
|[[#key-0-19| > 19]]
|-id=key-0-19
|19
|Spikes 8-12 cm long, straight, erect or inclined; blades 2-4 mm wide
|[[Elymus bakeri|Elymus bakeri]]
|-id=key-0-19
|19
|Spikes 7-30 cm long, flexuous, nodding to pendent; blades 5-14 mm wide
|[[Elymus sibiricus|Elymus sibiricus]]
|-id=key-0-18
|18
|Lemma awns usually straight or flexuous, or, if shorter than 10 mm, sometimes weakly curving.
|[[#key-0-19| > 19]]
|-id=key-0-20
|20
|Glumes with hairs on the adaxial (inner) surface, these often inconspicuous
|[[Elymus caninus|Elymus caninus]]
|-id=key-0-20
|20
|Glumes glabrous on the adaxial (inner) surface.
|[[#key-0-21| > 21]]
|-id=key-0-21
|21
|Palea keels distinctly outwardly curved below the apices, winged, not or scarcely extending beyond the intercostal region; apices 0.3-0.5 mm wide
|[[Elymus tsukushiensis|Elymus tsukushiensis]]
|-id=key-0-21
|21
|Palea keels straight or slightly outwardly curved below the apices, not winged, often extending beyond the intercostal region, sometimes forming teeth; apices 0.1-0.3 mm wide.
|[[#key-0-22| > 22]]
|-id=key-0-22
|22
|Glumes 1.8-2.3 mm wide, margins 0.2-0.3 mm wide
|[[Elymus trachycaulus|Elymus trachycaulus]]
|-id=key-0-22
|22
|Glumes 0.4-1.5(2) mm wide, margins 0.1-0.2 mm wide.
|[[#key-0-23| > 23]]
|-id=key-0-23
|23
|Spikes erect or almost so, 0.5-2 cm wide
|[[Elymus glaucus|Elymus glaucus]]
|-id=key-0-23
|23
|Spikes nodding to pendent, 2-5 cm wide
|[[Elymus sibiricus|Elymus sibiricus]]
|-id=key-0-17
|17
|Lemmas unawned or with awns up to 7 mm long.
|[[#key-0-18| > 18]]
|-id=key-0-24
|24
|Plants strongly rhizomatous
|[[Elymus lanceolatus|Elymus lanceolatus]]
|-id=key-0-24
|24
|Plants not or only shortly rhizomatous.
|[[#key-0-25| > 25]]
|-id=key-0-25
|25
|Glumes 1/3 – 2/3 as long as the adjacent lemmas.
|[[#key-0-26| > 26]]
|-id=key-0-26
|26
|Glumes 0.8-1.8 mm wide, lanceolate, margins subequal; lemmas evenly hairy or glabrous distally
|[[Elymus macrourus|Elymus macrourus]]
|-id=key-0-26
|26
|Glumes 1.5-2 mm wide, oblanceolate to obovate, margins unequal; lemmas glabrous, evenly hairy, or more densely hairy distally
|[[Elymus alaskanus|Elymus alaskanus]]
|-id=key-0-25
|25
|Glumes 3/4 as long as to slightly longer than the adjacent lemmas.
|[[#key-0-26| > 26]]
|-id=key-0-27
|27
|Glumes 3(5)-veined; glume margins unequal, the wider margins 0.3-1 mm wide, usually widest in the distal 1/3; lemma awns 0.5-3 mm long
|[[Elymus violaceus|Elymus violaceus]]
|-id=key-0-27
|27
|Glumes 3-7-veined, glume margins equal, 0.1-0.5 mm wide, widest at or slightly beyond midlength; lemmas unawned or with awns to 40 mm long.
|[[#key-0-28| > 28]]
|-id=key-0-28
|28
|Glumes 1.8-2.3 mm wide, margins 0.2-0.3 mm wide
|[[Elymus trachycaulus|Elymus trachycaulus]]
|-id=key-0-28
|28
|Glumes 0.4-1.5(2) mm wide, margins 0.1-0.2 mm wide
|[[Elymus glaucus|Elymus glaucus]]
|-id=key-0-1
|1
|Spikelets 2-3(5) at all or most nodes; glumes often with subterete to terete, indurate bases, sometimes with flat, non-indurate bases, glume bodies linear-lanceolate to setaceous or subulate, margins usually firm, sometimes hyaline or scarious; lemmas usually awned, awns up to 120 mm long [for opposite lead, see p. 290].
|[[#key-0-2| > 2]]
|-id=key-0-29
|29
|Rachises disarticulating at maturity; glumes 10-135 mm long including the awns, sometimes split longitudinally, flexuous to outcurving from near the base; lowest floret in each spikelet sometimes sterile; blades 1-6 mm wide.
|[[#key-0-30| > 30]]
|-id=key-0-30
|30
|Glume awns split into 3-9 divisions; lemma awns about 0.2 mm wide at the base; rachis internodes 3-5 mm long
|[[Elymus multisetus|Elymus multisetus]]
|-id=key-0-30
|30
|Glume awns entire or split into 2-3 divisions; lemma awns about 0.4 mm wide at the base; rachis internodes 3-10(15) mm long
|[[Elymus elymoides|Elymus elymoides]]
|-id=key-0-29
|29
|Rachises not disarticulating at maturity; glumes 0-43 mm long including the awns, entire, straight or outcurving from well above the base; lowest floret in each spikelet functional; blades 2-25 mm wide.
|[[#key-0-30| > 30]]
|-id=key-0-31
|31
|Glume bodies with 0-1(2) veins, linear or tapering from the base, 0.1-0.6 mm wide, 0-24 mm long including the awns, often differing in length by more than 5 mm, persistent after the florets disarticulate; rachis internodes 0.1-0.3(0.4) mm thick at the thinnest sections, often with green lateral bands.
|[[#key-0-32| > 32]]
|-id=key-0-32
|32
|Spikelets widely divergent to patent at maturity; lemma awns usually straight, rarely slightly curving; glumes vestigial or 1-3 mm long, occasionally some unequal glumes up to 10(20) mm long and 0.1-0.2 mm wide but with no distinct vein; spikes more or less erect
|[[Elymus hystrix|Elymus hystrix]]
|-id=key-0-32
|32
|Spikelets usually appressed, never widely divergent; lemma awns straight or curving; glumes sometimes vestigial, usually 1-24 mm long, 0.1-0.6 mm wide, often with 1(2) distinct veins; spikes erect, nodding, or pendent.
|[[#key-0-33| > 33]]
|-id=key-0-33
|33
|Glumes 12-30 mm long including the awns, subequal; lemma awns straight to moderately curving; spikes erect to slightly nodding.
|[[#key-0-34| > 34]]
|-id=key-0-34
|34
|Spikelets (6)9-15(22) mm long excluding the awns, each with 2-5 florets; lemma awns moderately outcurving at maturity; glumes (0.2)0.3-0.5(0.7) mm wide
|[[Elymus interruptus|Elymus interruptus]]
|-id=key-0-34
|34
|Spikelets 18-40 mm long excluding the awns, each with 3-8 florets; lemma awns straight to slightly curving at maturity; glumes 0.1-0.3(0.6) mm wide.
|[[#key-0-35| > 35]]
|-id=key-0-35
|35
|Anthers 2.5-4 mm long; lemmas scabrous-hispid to thinly strigose, at least distally; spikes 4-12 cm long; internodes 3-6 mm long, without green lateral bands, with hispid dorsal angles
|[[Elymus pringlei|Elymus pringlei]]
|-id=key-0-35
|35
|Anthers 4.5-6 mm long; lemmas smooth, glabrous; spikes 9-20 cm long; internodes (5)7-15(22) mm long, with green lateral bands, glabrous except for the ciliolate margins
|[[Elymus texensis|Elymus texensis]]
|-id=key-0-33
|33
|Glumes 0-15(30) mm long including the awns, usually differing in length by at least 4 mm, 1 or both shorter than 12 mm, sometimes both essentially absent; lemma awns outcurving at maturity; spikes more or less nodding.
|[[#key-0-34| > 34]]
|-id=key-0-36
|36
|Rachis internodes 4-6(9) mm long; lemmas hirsute to strigose, at least near the margins, awns 20-35 mm long; sheaths glabrous; plants not glaucous or moderately glaucous
|[[Elymus diversiglumis|Elymus diversiglumis]]
|-id=key-0-36
|36
|Rachis internodes (4)6-13(18) mm long; lemmas glabrous or pubescent, awns (8)10-30(35) mm long; sheaths glabrous or villous; plants usually glaucous, sometimes strongly so.
|[[#key-0-37| > 37]]
|-id=key-0-37
|37
|Lemmas usually glabrous, veins occasionally hispidulous near the apices, awns (8)10-20(25) mm long; spikelets with (3)4-5 florets; rachis internodes (4)6-10(12) mm long, without green lateral bands, glabrous; adaxial surfaces of the blades usually villous; plants strongly glaucous
|[[Elymus svensonii|Elymus svensonii]]
|-id=key-0-37
|37
|Lemmas usually hairy, awns (10)20-30(35) mm long; spikelets with 3(5) florets; rachis internodes (5)7-13(18) mm long, with green lateral bands and hispid dorsal angles; adaxial surfaces of the blades glabrous or short-pilose; plants somewhat glaucous
|[[Elymus churchii|Elymus churchii]]
|-id=key-0-31
|31
|Glume bodies with 2-5(8) veins, widening or parallel-sided above the base, (0.2)0.3-2.3 mm wide, 4-43 mm long including the awns, equal or subequal, persistent or disarticulating; rachis internodes 0.1-0.8 mm thick at the thinnest sections, usually lacking green lateral bands.
|[[#key-0-32| > 32]]
|-id=key-0-38
|38
|Glumes bases more or less terete, indurate, and without veins for 0.5-4 mm; glume bodies exceeding the adjacent lemmas by 1-5 mm or indistinguishable from the glume awns; lemma awns usually straight, occasionally contorted on the lower spikelets; rachis internodes (1.5)2-5(8) mm long.
|[[#key-0-39| > 39]]
|-id=key-0-39
|39
|Glumes persistent, glume bodies (0.2)0.3-0.8(1) mm wide, with 2-4 veins, the basal 0.5-2 mm straight or slightly curving; lemmas with hairs or scabrous; spikelets with 1-3(4) florets; spikes nodding, exserted from the sheath.
|[[#key-0-40| > 40]]
|-id=key-0-40
|40
|Adaxial surfaces of the blades densely villous with fine whitish hairs, rarely just pilose on the veins, dark glossy green; spikes 4-12 cm long; internodes (1.5)2-3(4) mm long; spikelets with 1-2(3) florets; lemmas usually villous, sometimes glabrous, sometimes scabrous, 5.5-9 mm long, 0.5-1.5 mm longer than the paleas; anthesis usually in early June to early July
|[[Elymus villosus|Elymus villosus]]
|-id=key-0-40
|40
|Adaxial surfaces of the blades glabrous or scabrous, dull green; spikes 7-25 cm long; internodes 3-5(8) mm long; spikelets with 2-3(4) florets; lemmas hispidulous or scabrous, 7-14 mm long, 1-5 mm longer than the paleas; anthesis usually in late June to late July
|[[Elymus riparius|Elymus riparius]]
|-id=key-0-39
|39
|Glumes disarticulating, glume bodies (0.5)0.7-2.3 mm wide, with (2)3-5(8) veins, the basal 1-4 mm clearly bowed out; lemmas often glabrous, sometimes scabrous; spikelets with 2-5(6) florets; spikes erect, exserted or sheathed.
|[[#key-0-40| > 40]]
|-id=key-0-41
|41
|Spikes (0.5)0.7-2.2(2.5) cm wide including the awns, exserted or sheathed; glume awns 0-10(15) mm long; spikelets appressed to slightly spreading; blades usually glabrous or scabridulous.
|[[#key-0-42| > 42]]
|-id=key-0-42
|42
|Lemma awns 5-15(20) mm long at midspike; blades of all leaves usually spreading or lax and flat, those of the lower leaves not markedly larger or more persistent than those of the upper leaves; anthesis in mid-June to mid-August, usually 1-2 weeks earlier than sympatric E. curvatus
|[[Elymus virginicus|Elymus virginicus]]
|-id=key-0-42
|42
|Lemma awns 0.5-3(4) mm long at midspike; upper blades usually ascending and somewhat involute, blades of the lower leaves relatively short, narrow, and senescing earlier than those of the upper leaves; anthesis usually in late June to early August, 1-2 weeks later than sympatric E. virginicus
|[[Elymus curvatus|Elymus curvatus]]
|-id=key-0-41
|41
|Spikes (1.7)2.2-4.5(5.5) cm wide including the awns, exserted; glume awns (10)15-30 mm long; spikelets spreading; blades glabrous or villous.
|[[#key-0-42| > 42]]
|-id=key-0-43
|43
|Spikes with (6)9-16(20) nodes; internodes 4-7 mm long, about 0.3 mm thick at the thinnest portion; blades lax, dark glossy green under the glaucous bloom; auricles 2-3 mm long, often purplish black, at least in the central range of the species; anthesis usually in mid-May to mid-June
|[[Elymus macgregorii|Elymus macgregorii]]
|-id=key-0-43
|43
|Spikes with (10)18-30(36) nodes; internodes 3-5 mm long, 0.3-0.8 mm thick at the thinnest portion; blades lax, or ascending and involute, usually dull green, with or without a glaucous bloom; auricles 0-2 mm long, usually purplish brown; anthesis usually in mid-June to late July
|[[Elymus glabriflorus|Elymus glabriflorus]]
|-id=key-0-38
|38
|Glume bases flat and veined or, if subterete to terete, indurate and without veins for less than 1 mm; glume bodies shorter than or subequal to the lowest lemmas; lemma awns usually flexuous to curving, sometimes straight; rachis internodes (2)3-14 mm long.
|[[#key-0-39| > 39]]
|-id=key-0-44
|44
|Glumes with more or less terete bases, without hyaline or scarious margins, always awned, awns (5)8-25(27) mm long or the glume bodies indistinguishable from the awns; spikelets (1)2-3(5) per node, spreading, not or rarely purplish; cauline nodes usually concealed by the sheaths.
|[[#key-0-45| > 45]]
|-id=key-0-45
|45
|Spikes erect to slightly nodding, internodes (5)8-14 mm long; glumes 0.2-0.5(0.7) mm wide; lemmas 7-10 mm long, usually smooth or scabrous, occasionally hirtellous, especially near the margins, awns 15-22 mm long, straight to moderately outcurving; blades 3-9 mm wide; culms (40)60-100(120) cm tall, nodes usually exposed
|[[Elymus interruptus|Elymus interruptus]]
|-id=key-0-45
|45
|Spikes usually nodding to pendent, sometimes erect, internodes (2)3-8(12) mm long; glume bodies (0.2)0.4-1.6 mm wide; lemmas 8-15 mm long, glabrous or uniformly hairy, awns (10)15-40(50) mm long, moderately to strongly outcurving; blades 3-24 mm wide; culms (40)60-180(220) cm tall, nodes usually concealed by the leaf sheaths.
|[[#key-0-46| > 46]]
|-id=key-0-46
|46
|Rachis internodes (2)3-5(7) mm long; spikelets 2(3) at most nodes, occasionally 1 or up to 5 at some nodes; paleas acute; blades (3)4-15(20) mm wide, usually firm and somewhat involute, dull green, drying grayish
|[[Elymus canadensis|Elymus canadensis]]
|-id=key-0-46
|46
|Rachis internodes 5-12 mm long; spikelets 2 per node; paleas narrowly truncate; blades (8)10-20(24) mm wide, flat, lax, dark green
|[[Elymus wiegandii|Elymus wiegandii]]
|-id=key-0-44
|44
|Glumes with flat bases and hyaline or scarious margins, usually awned, awns 1-10 mm long, sometimes unawned; spikelets (1)2(3) per node, appressed to divergent, sometimes purplish; cauline nodes mostly exposed.
|[[#key-0-45| > 45]]
|-id=key-0-47
|47
|Anthers 0.9-1.7 mm long; glumes 3-8 mm long; lowest lemmas 3-6 mm longer than the glumes, densely scabridulous to scabrous, awns usually outcurving; spikelets with (3)4-5(7) florets; spikes 2-5 cm wide, nodding to pendent; cauline nodes glabrous
|[[Elymus sibiricus|Elymus sibiricus]]
|-id=key-0-47
|47
|Anthers 1.5-4.5 mm long; glumes (4.5)6-14(19) mm long; lowest lemmas from shorter than to 2.5 mm longer than the glumes, smooth, sometimes hairy, awns straight, flexuous, or outcurving; spikelets with 2-4(7) florets; spikes (0.2)0.5-2.5 cm wide, erect, nodding, or pendent; cauline nodes occasionally with short hairs.
|[[#key-0-48| > 48]]
|-id=key-0-48
|48
|Glume bodies (6)9-14(19) mm long; lemmas 8-16 mm long, awns usually straight to flexuous; auricles usually present, to 2.5 mm long
|[[Elymus glaucus|Elymus glaucus]]
|-id=key-0-48
|48
|Glume bodies (4.5)6-10(11) mm long; lemmas 5-14 mm long, awns flexuous to moderately outcurving; auricles often absent, or to 1.5 mm long.
|[[#key-0-49| > 49]]
|-id=key-0-49
|49
|Lemmas with hairs, the marginal hairs markedly longer than those elsewhere; paleas acute; spikes nodding to pendent; rachis internodes 3-12 mm long; leaves usually deep green; plants native to the Pacific coastal mountains
|[[Elymus hirsutus|Elymus hirsutus]]
|-id=key-0-49
|49
|Lemmas smooth, scabrous, or hispid, the marginal hairs, if present, not markedly longer than those elsewhere; paleas obtuse or truncate; spikes erect to slightly nodding; rachis internodes 3-6 mm long; leaves usually pale green, sometimes glaucous; plants introduced
|[[Elymus dahuricus|Elymus dahuricus]]
|}
</div></div><!--

-->{{#Taxon:
name=Elymus
|author=Mary E. Barkworth; Julian J.N. Campbell; Bjorn Salomon;
|authority=L.
|rank=genus
|parent rank=tribe
|synonyms=
|basionyms=
|family=Poaceae
|distribution=Idaho;Mont.;Nebr.;N.C.;Conn.;N.J.;N.Y.;Mass.;Wash.;Va.;W.Va.;Ark.;Iowa;Kans.;Mo.;N.Dak.;Okla.;S.Dak.;Ariz.;D.C;Ga.;Ill.;Ky.;Mich.;N.Mex.;Pa.;S.C.;Tenn.;Wyo.;Del.;Miss.;Ind.;Oreg.;Maine;N.H.;R.I.;Vt.;Ala.;Fla.;La.;Md.;N.S.;Ohio;Tex.;Wis.;Colo.;Calif.;Alaska;Utah;Nev.;Alta.;B.C.;Greenland;Man.;N.B.;Nfld. And Labr.;N.W.T.;Nunavut;Ont.;P.E.I.;Que.;Sask.;Yukon;Minn.
|reference=barkworth1997a;barkworth2000a;barkworth2005a;bennett2006a;bodvarsdottir2003a;booher1948a;bowden1958a;bowden1964a;bowden1967a;brooks1974a;brown1960a;bush1926a;campbell2000a;campbell2002a;campbell2002b;church1954a;church1958a;church1967a;church1967b;davies1980a;dewey1963a;dewey1965a;dewey1967a;dewey1967b;dewey1968a;dewey1970a;dewey1974a;dewey1975a;dewey1976a;dewey1982a;gabel1984a;gillett1960a;gillett1961a;godley1947a;hitchcock1935a;hitchcock1951a;hitchcock1969d;hulten1968a;jensen-a;jensen1993a;jones1988b;jozwik1966a;lepage1952a;lepage1965a;love1984a;mason-gamer2001a;nelson1978a;pohl1959a;pohl1966a;porsild1980a;pyrah1983a;salomon1991a;sanders1979a;smith1991a;snyder1950a;snyder1951a;stebbins1956a;stebbins1957a;steyermark1963b;sun1998a;sun2003a;sun2006a;svitashev1998a;tsvelev1976a;vilkomerson1950a;wilson1963a;wilson2001a;yen2005b;zhang2002b
|publication title=
|publication year=
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f6b125a955440c0872999024f038d74684f65921/coarse_grained_fna_xml/V24/V24_415.xml
|subfamily=Poaceae subfam. Pooideae
|tribe=Poaceae tribe Triticeae
|genus=Elymus
}}<!--

-->[[Category:Treatment]][[Category:Poaceae tribe Triticeae]]