Leymus mollis (Trin.) Pilg. subsp. mollis
dune wildrye (American dunegrass)
Poaceae (Grass family)

Introduction to Vascular Plants


© Tim de Lange Boom     (Photo ID #23586)


E-Flora BC Static Map

Distribution of Leymus mollis subsp. mollis
Click here to view the full interactive map and legend

Species Information

Perennial, tufted grass from thick, ascending rhizomes forming large clumps; stems erect, stout, usually finely but copiously hairy or sometimes smooth above, 50-150 cm tall.
Sheaths open, smooth; blades tough, very finely minutely rough appressed-hairy on the upper surfaces and smooth underneath, with numerous prominent nerves, flat to in-rolled, 6-15 mm wide; ear-shaped lobes usually developed at some leaf-bases; ligules more or less fringed with fine hairs, scarcely 1 mm long.
Inflorescence a stout spike, (10) 15-30 cm long, 1-2 cm wide; spikelets paired, 4- to 6-flowered, unstalked or if occasionally short-stalked then inflorescence slightly compounded, 20-30 (33) mm long; glumes lanceolate, usually soft-hairy but sometimes only sparsely short-hairy, prominently 3- to 6-nerved and flat, at least at the base, usually membranous-margined, long-pointed, mostly nearly equal to the spikelets, 15-25 mm long, awn-tipped; lemmas generally copiously soft-hairy but rarely only sparsely hairy, mostly prominently-nerved, membranous-margined, 10-20 mm long, long-pointed to abruptly slender-tipped, but scarcely awned; anthers 5-9 mm long.
A hybrid between Leymus mollis and Elymus glaucus, known only from Ucluelet and Gold River, has been named Leymus x uclueletensis (Bowden) Baum (Elymus x uclueletensis Bowden). A second hybrid, which is infrequent in SW BC, Leymus x vancouverensis (Vasey) Pilger (Elymus vancouverensis Vasey), has been proposed as a hybrid between Leymus mollis and L. triticoides (Buckl.) Pilger. See Hitchcock et al. (1969) for more detailed descriptions of these hybrids.

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:
Late Spring
Fruit/Seed characteristics:
Colour: Brown
Present from Summer to Fall
Source:  The USDA


Ecological Framework for Leymus mollis ssp. mollis

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)
3 0 11
Slope Gradient (%)
7 0 40

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

Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
2 1 6
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

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


Habitat and Range

Moist to mesic sandy or gravelly beaches and shoreline forests in the lowland zone; common in coastal BC; amphiberingian, N to AK, YT and N, E to NF and S to NH, PA, MI, IL and CA; Greenland, E Asia.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Elymus arenarius
Elymus arenarius subsp. mollis (Trin.) Hultén
Elymus arenarius var. scabrinervis (Bowden) B. Boivin
Elymus arenarius var. villosus E. Mey.
Elymus capitatus Scribn.
Elymus mollis Trin.
Elymus mollis var. mollis
Leymus arenarius subsp. mollis (Trin.) Tzvelev