E-Flora BC: Electronic Atlas of the Flora of British Columbia

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

Introduction to Vascular Plants

© Adolf Ceska  Email the photographer   (Photo ID #20757)

E-Flora BC Static Map
Distribution of Agrostis scabra
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Species Information

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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.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

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

Habitat / 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.

Source: The Illustrated Flora of British Columbia


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) 8 1138 2400
Slope Gradient (%) 0 14 230
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
2 196 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 4 8
Modal Nutrient Regime
Number 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)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

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.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References