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Vascular Plants of California
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Elymus
WILD-RYE, WHEAT GRASS, SQUIRRELTAIL


Higher Taxonomy
Family: Poaceae (Gramineae)View DescriptionDichotomous Key

Common Name: GRASS FAMILY
Habit: Annual to woody perennial herb; roots generally fibrous. Stem: generally round, hollow; nodes swollen, solid. Leaf: alternate, 2-ranked, generally linear, parallel-veined; sheath generally open; ligule membranous or hairy, at blade base. Inflorescence: various (of generally many spikelets). Spikelet: glumes generally 2; florets (lemma, palea, flower) 1--many; lemma generally membranous, sometimes glume-like; palea generally +- transparent, +- enclosed by lemma. Flower: generally bisexual, minute; perianth vestigial; stamens generally 3; stigmas generally 2, generally plumose. Fruit: grain, sometimes achene- or utricle-like.
Genera In Family: 650--900 genera; +- 10550 species: worldwide; greatest economic importance of any family (wheat, rice, maize, millet, sorghum, sugar cane, forage crops, ornamental, weeds; thatching, weaving, building materials). Note: Generally wind-pollinated. Achnatherum, Ampelodesmos, Hesperostipa, Nassella, Piptatherum, Piptochaetium, Ptilagrostis moved to Stipa; Elytrigia, Leymus, Pascopyrum, Pseudoroegneria, Taeniatherum to Elymus; Hierochloe to Anthoxanthum; Lolium, Vulpia to Festuca; Lycurus to Muhlenbergia; Monanthochloe to Distichlis; Pleuraphis to Hilaria; Rhynchelytrum to Melinis. The following taxa (in genera not included here), recorded in California from historical collections or reported in literature, are extirpated, lacking vouchers, or not considered naturalized: Acrachne racemosa (Roth) Ohwi, Allolepis texana (Vasey) Soderstr. & H.F. Decker, Amphibromus nervosus (Hook. f.) Baill., Axonopus affinis Chase, Axonopus fissifolius (Raddi) Kuhlm., Coix lacryma-jobi L., Cutandia memphitica (Spreng.) K. Richt., Dinebra retroflexa (Vahl) Panz., Eremochloa ciliaris (L.) Merr., Eustachys distichophylla (Lag.) Nees, Gaudinia fragilis (L.) P. Beauv., Miscanthus sinensis Andersson, Neyraudia arundinacea (L.) Henrard, Phyllostachys aurea Rivière & C. Rivière, Phyllostachys bambusoides Siebold & Zuccarini, Rottboellia cochinchinensis (Lour.) Clayton, Schedonnardus paniculatus (Nutt.) Branner & Coville, Schizachyrium cirratum (Hack.) Wooton & Standl., Schizachyrium scoparium (Michx.) Nash, Themeda quadrivalvis (L.) Kuntze, Thysanolaena latifolia (Hornem.) Honda, Tribolium obliterum (Hemsl.) Renvoize, Zea mays L., Zizania palustris L. var. interior (Fassett) Dore, Zoysia japonica Steud. Paspalum pubiflorum E. Fourn., Paspalum quadrifarium Lam., are now reported for southern California (J Bot Res Inst Texas 4:761--770). See Glossary p. 30 for illustrations of general family characteristics.
eFlora Treatment Author: James P. Smith, Jr., except as noted
Scientific Editor: James P. Smith, Jr., J. Travis Columbus, Dieter H. Wilken.
Elymus
Habit: Annual, perennial herb, rhizomes 0 to well developed. Stem: generally bent at base or erect, generally tufted. Leaf: auricles present, occasionally small, fragile; ligule membranous, truncate to obtuse; blade flat, folded, or rolled. Inflorescence: spike-like (raceme-like or panicle-like), open to dense; axis generally remaining intact with age; spikelets 1--3(7) at all or most nodes, generally ascending. Spikelet: compressed laterally, glumes generally lanceolate to awn-like, occasionally 0, awned from tip or not; florets 1--11; breaking apart above glumes and between florets; lemma generally > glumes, generally rounded, 5--7-veined, tip generally acute to awned, awn straight or curved outward; palea <, =, or > lemma or 0; anthers 3(1), 1--8 mm.
Species In Genus: +- 235 species: temperate worldwide. Etymology: (Greek: covered, a reference to grain being tightly covered by palea and lemma) Note: References to number of spikelets per node is best understood as "most, if not all" and best determined by examining nodes in middle of inflorescence. Intergeneric and interspecific hybrids, along with effects of soil moisture on plant growth, render keys even more challenging and frustrating than usual. As treated here, genus includes taxa previously assigned to Agropyron (in part), Elytrigia, Leymus, Pascopyrum, Pseudoroegneria, and Taeniatherum. Elymus ×aristatus Merr., Elymus arizonicus (Scribn. & J.G. Sm.) Gould, Elymus canadensis L., Elymus interruptus Buckley, Agropyron junceum (L.) P. Beauv. [Thinopyrum junceum (L.) Á. Löve], and Elymus pycnanthus (Godr.) Melderis [Thinopyrum pycnanthum (Godr.) Barkworth] have been reported for California, may occur sporadically, but do not appear to have become naturalized. Intergeneric hybrids involving Hordeum constitute the genus ×Elyhordeum and are cited in species descriptions. Elymus farctus (Viv.) Melderis subsp. boreo-atlanticus (Simonet & Guin.) Melderis [Elytrigia juncea (L.) Nevski subsp. boreo-atlantica (Simonet & Guin.) Hylander] naturalized, under eradication at Oceano Dunes.
Jepson eFlora Author: James P. Smith, Jr.
Reference: Barkworth 2007 FNANM 24:283--287, 348--351, 353--369, 373--378
Unabridged Reference: Barkworth & Dewey 1985 Amer J Bot 72:767--776; Barkworth et al. 2007 FNANM 24:288--343; Carlson 2007 FNANM 24:279--282; Gould 1947 Madroño 9:120--128; Wipff 2007 FNANM 24:257, 258
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)
Key to Elymus

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Citation for this treatment: James P. Smith, Jr. 2012, Elymus, in Jepson Flora Project (eds.) Jepson eFlora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=11052, accessed on April 19, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora, https://ucjeps.berkeley.edu/eflora/, accessed on April 19, 2024.