Elymus repens (L.) Gould
quackgrass (creeping wildrye)
Poaceae (Grass family)

Introduction to Vascular Plants


© Jamie Fenneman     (Photo ID #10339)


E-Flora BC Static Map

Distribution of Elymus repens
Click here to view the full interactive map and legend

Species Information

Perennial grass from extensive rhizomes; stems erect to decumbent, 50-100 cm tall/long, the nodes exposed, smooth.
Sheaths smooth or hairy; blades 6-10 mm wide, flat, the undersides smooth, the upper surfaces rough along the nerves, ear-shaped lobes at the leaf-bases 0.3-1 mm long; ligules 0.25-1.5 mm long, membranous.
Inflorescence a spike 5-15 cm long, 5-10 mm wide, erect, with 1 spikelet per node; spikelets 10-27 mm long, more than 2 times as long as the internodes, with 4 to 7 florets; glumes unequal, 7-10 mm long, with transparent edges along the upper 1/2, the tips pointed; lemmas 8-10.4 mm long, awnless or awned, the awns 0.2-3.8 (10) mm long; anthers 4-7 mm long.

SourceThe Illustrated Flora of British Columbia


If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

USDA Species Characteristics

Flower Colour:
Blooming Period:
Mid Spring
Fruit/Seed characteristics:
Colour: Brown
Present from Spring to Summer
According to the USDA, this species is a known allelopath.
Source:  The USDA


Ecological Framework for Elymus repens

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres)
920 20 2140
Slope Gradient (%)
10 0 80

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

181 12 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
4 0 8
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

All BEC Zones (# of stations/zone) species was recorded in

BG(35), BWBS(5), CWH(12), ESSF(18), ICH(10), IDF(116), MS(18), PP(30), SBPS(16), SBS(4)

Habitat and Range

Mesic to dry roadsides, fields, gardens and disturbed sites in the lowland, steppe and montane zones; common in S BC south of 51 degrees N, less frequent N to 55degree N; introduced from Eurasia.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Agropyron repens
Agropyron repens var. subulatum (Schreb.) Roemer & J.A. Schultes
Elytrigia repens
Elytrigia repens var. vaillantiana (Wulfen & Schreb.) Prokudin
Elytrigia vaillantiana (Wulfen & Schreb.) Beetle
Triticum repens L.
Triticum vaillantianum Wulfen & Schreb.