Agrostis scabra Willd.
hair bentgrass (rough bentgrass; winter bentgrass)
Poaceae (Grass family)

Introduction to Vascular Plants


© Adolf Ceska     (Photo ID #20757)


E-Flora BC Static Map

Distribution of Agrostis scabra
Click here to view the full interactive map and legend

Species Information

Perennial, densely tufted grass from fibrous roots; stems 20-75 cm tall.
Sheaths smooth, blades mostly basal, 4-14 cm long, 1-3 mm wide, flat, finely rough short-hairy; ligules 2-5 mm long.
Inflorescence broadly egg-shaped, open, large, upright, 10-30 cm long, about as wide as long, very diffuse with hairlike, lax branches 8-25 cm long, frequently detaching at maturity, the lower branches 4-11 cm long, broadly spreading at maturity, branched 1 or 2 times above the middle, the spikelets few, broadly separated at the tips of the branches, not near the base; glumes 1.5-3 mm long, rough short-hairy on the keels; lemmas 1.5-2 mm long, awnless or sometimes awned from below the middle on the back, the awns to 2 mm long, more or less straight, the callus hairs minute; paleas absent or if present, minute, less than 1/4 as long as the lemmas; anthers 0.4-0.7 mm long.
Agrostis perennans (Walt.) Tuckerm., hitherto regarded as an eastern species, has recently been found in WA and can be expected in BC. It differs from A. scabra in its slightly more condensed but still hairlike inflorescence and few or no basal leaves at flowering time but several well-developed stem leaves. It grows on moist to wet cliffs and streamsides. See also comments under A. idahoensis.

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:
Early Spring
Fruit/Seed characteristics:
Colour: Brown
Present over the Summer
Source:  The USDA


Ecological Framework for Agrostis scabra

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)
1138 8 2400
Slope Gradient (%)
14 0 230

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

196 2 360
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(5), BWBS(17), CDF(5), CMA(1), CWH(52), ESSF(123), ICH(77), IDF(67), MH(15), MS(104), PP(1), SBPS(41), SBS(116), SWB(2)

Habitat and Range

Moist to dry meadows, rock outcrops, forest openings, clearings and roadsides in the lowland to subalpine zones; common throughout BC; amphiberingian, N to AK, YT and NT, E to NF, S to ME, MA, PA, NC, FL, MS, LA, TX, NM, AZ, MX and CA; Greenland, NE Asia.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Agrostis geminata Trin.
Agrostis hyemalis (Walter) Britton, Sterns & Poggenb.
Agrostis hyemalis var. geminata (Trin.) A.S. Hitchc.
Agrostis hyemalis var. scabra (Willd.) Blomquist
Agrostis hyemalis var. tenuis (Tuckerman) Gleason
Agrostis scabra subsp. septentrionalis (Fern.) A.& D. L÷ve
Agrostis scabra var. geminata (Trin.) Swallen
Agrostis scabra var. septentrionalis Fern.