Agrostis pallens Trin.
dune bentgrass (seashore bentgrass; thingrass)
Poaceae (Grass family)

Introduction to Vascular Plants


© Hans Roemer     (Photo ID #10221)


E-Flora BC Static Map

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

Species Information

Perennial grass from rhizomes to about 10 cm long, rhizomes sometimes absent, not forming a turf and including many non-flowering shoots; stems 10-70 cm tall, scattered.
Sheaths smooth; blades 1.5-5 cm long, 1-6 mm wide, flat, becoming in-rolled; ligules 1.5-6 mm long, rough-hairy outside.
Inflorescence lanceolate to narrowly constricted, at least twice as long as wide, the branches ascending, 2-5 cm long; spikelets numerous; glumes 2-3 mm long; lemmas 1.5-2.5 mm long, awnless or rarely with straight awns to 0.5 mm long, from below the tips, calluses with sparse hairs to 0.25 mm long; paleas absent or if present, thin membranes to 0.2 mm long; anthers 1-1.7 mm long.
This is a rare species or group of species formerly thought to be confined to sand dunes but now known to occur inland in habitats subject to extreme summer drought.

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 over the Summer
Source:  The USDA


Ecological Framework for Agrostis pallens

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)
218 130 324
Slope Gradient (%)
29 0 84

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

180 180 180
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
4 0 7
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

Dry sand dunes, meadows, rock outcrops and rocky slopes in the lowland zone; rare on Vancouver Island and the Queen Charlotte Islands; S to MT, ID, NV and CA.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Agrostis diegoensis Vasey
Agrostis lepida Hitchc.
Agrostis pallens var. vaseyi H. St. John