Jepson eFlora: Taxon page
Key to families | Table of families and genera
Previous taxon Index to accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Next taxon
Elymus trachycaulus subsp. trachycaulus
SLENDER WHEAT GRASS

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.
Genus: ElymusView DescriptionDichotomous Key

Common Name: WILD-RYE, WHEAT GRASS, SQUIRRELTAIL
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.

Elymus trachycaulus (Link) Gould ex Shinners subsp. trachycaulus
NATIVE
Habit: Cespitose or weakly rhizomatous. Stem: 3--15 dm. Leaf: sheath glabrous to hairy, auricles < 1 mm; ligule 0.2--0.8 mm; blade 2--5 (8) mm wide, flat to rolled. Inflorescence: 4--25 cm; sometimes appearing 1-sided because of twisting of spikelets to 1 side; spikelet 1 per node; internodes generally 7--9 mm. Spikelet: 10--20 mm; glumes 6--17 mm, lanceolate to narrowly ovate; florets 3--9; acute to short-awned; lemma 6--13 mm, glabrous to hairy, awn 1--40 mm; palea = lemma; anthers 1--2.5 mm. Chromosomes: 2n=28.
Ecology: Dry to moist, open areas, forest, woodland; Elevation: < 3400 m. Bioregional Distribution: CA (exc GV); Distribution Outside California: to Alaska, eastern United States, Greenland, Mexico. Flowering Time: Jun--Aug Note: Another subsp. is found in Greenland; forms hybrids with Agropyron cristatum, Elymus elymoides, Elymus glaucus, Elymus lanceolatus, Elymus scribneri. Hybrids with Hordeum jubatum are called ×Elyhordeum macounii (Vasey) Barkworth & D.R. Dewey.
Synonyms: Agropyron trachycaulum (Link) Malte ex H.F. Lewis; Elymus trachycaulus subsp. subsecundus (Link) Á. Löve & D. Löve
eFlora Treatment Author: James P. Smith, Jr.
Jepson Online Interchange

Previous taxon: Elymus stebbinsii
Next taxon: Elymus triticoides

Name Search
botanical illustration including Elymus trachycaulus subsp. trachycaulus

Contact/Feedback

Citation for this treatment: James P. Smith, Jr. 2016. Elymus trachycaulus subsp. trachycaulus, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=50280, accessed on December 09, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on December 09, 2016.


Elymus trachycaulus subsp. trachycaulus
click for enlargement
© 2007 Steve Matson
Elymus trachycaulus subsp. trachycaulus
click for enlargement
© 2007 Steve Matson
Elymus trachycaulus subsp. trachycaulus
click for enlargement
© 2007 Steve Matson
Elymus trachycaulus subsp. trachycaulus
click for enlargement
© 2007 Steve Matson
Elymus trachycaulus subsp. trachycaulus
click for enlargement
© 2007 Steve Matson
Elymus trachycaulus subsp. trachycaulus
click for enlargement
© 2007 Steve Matson

More photos of Elymus trachycaulus subsp. trachycaulus in CalPhotos


Geographic subdivisions for Elymus trachycaulus subsp. trachycaulus:
CA (exc GV);
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
READ ABOUT YELLOW FLAGS
map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

View elevation by latitude chart
Data provided by the participants of the Consortium of California Herbaria.
View all CCH records

CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.