Canada wildrye

Elymus canadensis L. 

Alternate Common Name(s): nodding wildrye, western wildrye, great plains wildrye

Scientific Synonym(s): Elymus brachystachys Scribn. & C.R. Ball, Elymus canadensis L. var. brachystachys  (Scribn. & C.R. Ball) Farw., Elymus canadensis L. var. hirsutus (Farw.) Dorn, Elymus canadensis L. var. robustus (Scribn. & J.G. Sm.) Mack. & Bush, Elymus crescendus L.C. Wheeler, Elymus philadelphicus L., Elymus philadelphicus L. var. hirsutus Farw., Elymus robustus Scribn. & J.G. Sm.

Family: ‌grass family (Poaceae)

Functional Group: cool season grasses

Description 

Life cycle and growth form

Perennial, cool-season bunchgrass, weak to no rhizomes.

Height: 1-5 ft  

Leaves and stem

Leaf blades up to 16 in long, 1/4-3/4 in wide, ligule a short (up to 1 mm) membrane, sheaths usually smooth with two small, purplish to brown lobes (auricles) clasping stem where the sheath meets the blade, nodes hairless and hidden under the sheaths; stems smooth, erect, unbranched.

Flower, fruit and seedhead

Fruit/seedhead: Seedhead a thick, bristly spike, 3-10 inches long, usually nodding, light tan when mature, each spikelet with a pair of awned glumes (up to 1.5 in including the awn) and 3-5 florets, lemmas (chaffy parts around the grain) also awned (up to 2.5 in including the awn), awns twist and curve outward when dry, florets drop when mature, leaving glumes on the stalk.

Pollination: wind

Seed

Appendix D

‌Seed characteristics 

Seeds per ounce: 5,200 (IA NRCS)

Seeds per pound: 83,200 (IA NRCS)

1000 seed weight: 4.50 g (Seed Information Database)

Description: The long, barbed awns make this species difficult to clean. Curved awns on lemmas are up to 5 cm (2 in). Glumes taper to awns 1-3 cm (1/2-1.25 in) long. Caryopsis dark brown at maturity, 5-8 mm long.

Typical seed test 

PLS: 88%

Purity: 96%

Germination: 66%

Dormant: 19%

(averages obtained from 12 tests of purchased seed lots)

Habitat and range

‌Habitat: Broadly adapted to a range of conditions: dry to moist soil; partial to full sun; prairies, savannas, woodland edges, bluffs, dunes, riverbanks, upland and lowland, open areas, disturbed areas. Wetland Indicator Status is Facultative Upland (FACU) for the Midwest. Well-drained, loamy soils are preferred for production.

Conservation status: Global- G5, secure; Maine- SH, possibly extirpated; Nevada and Virginia- S1, critically imperiled (NatureServe) 

General Comments

Canada wildrye is a relatively short-lived perennial bunchgrass which establishes readily from seed in mixed plantings. These two traits make it ideally suited as a nurse crop for prairie restorations. It can also be direct-seeded as a seed production field into a well-prepared, weed-free seed bed (e.g., following a glyphosate-resistant crop).

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

Row spacing:	36 in	24 in	12 in	solid stand
PLS lbs/acre:	7	10.5	21	21

Seeding depth: 1/4-1/2 in

Seeding method: native seed drill

Seeding time: Fall, or early spring preferred.

Weed control: Prepare clean, firm, weed free seedbed prior to seeding.

 

‌‌Greenhouse

Seed pre-treatment: No stratification necessary. Germination of grass seed usually improves with proper storage (cool, dry conditions) throughout the first year after harvest.

Sowing: Sow seed in greenhouse two months before last frost free date at 1/4 in depth.

Transplanting: Transplant at 12 in spacing in prepared beds after all danger of frost.

‌Appendix A

Stand management

Weeds: Mow stands high (6–12 in) first growing season to prevent weed canopy from shading seedlings. Broadleaf herbicides can be used to control broadleaf weeds in established stands.

Pests: None noted.

Diseases: Susceptible to leaf and stem rust, also ergot.

Hybridization risk: This species is known to hybridize with related species Elymus hystrix, E. villosus, E. virginicus

Seed production

First harvest: Flowering and seed set will occur at the end of the first growing season from previous fall seeding or early spring seeding, or late spring transplants.

Yield: 35-370 bulk pounds/acre (per acre yield extrapolated from 3 plots)

Stand life: 4-6 years. Seed production declines significantly in the fifth year and after. Annual fall burning will prolong stand life and seed yield.

Flowering date: mid-July to mid-August in northern Iowa

Seed maturity/Harvest date: September in northern Iowa

Seed retention: shattering occurs early to mid-October

Harvest date range at TPC (2003-2010): Sept 7 - Nov 4 

Recommended harvest method: Combine at maturity (hard dough stage). Long, barbed awns make harvesting a challenge, causing seed to ball up and not flow. Additional de-awning bars or other modifications to the combine may be required for successful harvest of this species.

Appendix B

Seed cleaning and storage

Cleaning process: Debeard or brush to remove long awns and make the material flowable. Air-screen to clean (See Appendix C for settings).

Seed storage: cool/dry (33-50° F, 30-50% RH)

Appendix C

Released Germplasm 

Source Identified material: Central Iowa Germplasm (IA Zone 2), Northern Iowa Germplasm (IA Zone 1), Southern Iowa Germplasm (IA Zone 3)

Selected Germplasm: Lavaca Germplasm (TX)

Cultivated variety (cultivar): Mandan (ND) 

Tested: Icy Blue Germplasm (MI)

References

Barkworth, M. E., Campbell, J. J.N., & Salomon, B. (2021, May 11). Elymus canadensis L. Flora of North America. http://floranorthamerica.org/Elymus_canadensis 

Chayka, K. (n.d.). Elymus canadensis (Canada wild rye). Minnesota Wildflowers. https://www.minnesotawildflowers.info/grass-sedge-rush/canada-wild-rye 

Cochrane, T. S., Elliot, K., & Lipke, C. S. (2014). Canada wild-rye. In Prairie plants of the University of Wisconsin-Madison Arboretum (3rd ed., p. 264). University of Wisconsin-Madison Arboretum.

Great Plains Flora Association. (1991). Grass family. In T. M. Barkley, R. E. Brooks, & E. K. Schofield (Eds.), Flora of the Great Plains (2nd ed., p. 1167). University Press of Kansas.

Houseal, G. A. (2007). Grasses cool season. In G. A. Houseal (Eds.), Tallgrass Prairie Center’s native seed production manual (pp. 84–85). Tallgrass Prairie Center - University of Northern Iowa.

Kartesz, J.T., The Biota of North America Program (BONAP). 2023. North American Plant Atlas. (http://bonap.net/napa). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2023. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]

NatureServe. 2024. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. (Accessed: February 29, 2024).

USDA NRCS National Plant Data Team. (n.d.). Elymus canadensis L. USDA plants database. https://plants.usda.gov/home/plantProfile?symbol=ELCA4

Species Guide Updated 01/31/2025