Poa macrantha Vasey
dune bluegrass (seashore bluegrass)
Poaceae (Grass family)

Introduction to Vascular Plants


© Adolf Ceska     (Photo ID #20377)


E-Flora BC Static Map

Distribution of Poa macrantha
Click here to view the full interactive map and legend

Species Information

Perennial, loosely tufted grass from fibrous roots, rhizomes and stolons, these shoots stout, to 4 m long; stems erect or decumbent, stout, 10-60 cm tall/long.
Sheath margins open about 1/2 their length, sheaths hairless or sparsely rough, the projections pointed downward; sterile shoots mainly emerging inside sheaths with well developed two-keeled buds protecting the scales; blades 2-4 mm wide, somewhat curved, in-rolled, thick, outer surface smooth, inner surface of sterile shoots usually distinctly rough or minutely soft-hairy; ligules 1-5 mm long, the tips rounded to sharp-pointed, the backs rough.
Inflorescence an erect panicle, 3-15 cm long, congested, often interrupted; stalks smooth to moderately rough, hairless; central axis and branches slightly to moderately rough, branches 1 to 2 per node; spikelets laterally compressed, 9-16 mm long, 3- to 6-flowered; lower glumes 3-nerved, the upper ones usually more than 7 mm long; rachillas smooth, silky-hairy (rarely hairless); lemmas lanceolate, (6) 7.5-11 mm long, the tips sharp-pointed, 5- to 7- (11-) nerved, surface smooth or rough, the keels, marginal nerves and some lateral nerves minutely soft- to short silky-hairy, smooth and hairless to rough or minutely soft-hairy between the nerves; calluses hairless, diffusely short-cobwebby, or with a crown of wavy hairs; palea keels rough; flowers unisexual; anthers vestigial or 2-5 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:
Late Winter
Fruit/Seed characteristics:
Colour: Brown
Present over the Spring
Source:  The USDA


Ecological Framework for Poa macrantha

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)
5 0 13
Slope Gradient (%)
3 0 20

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

232 200 280
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 1 2
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

Shifting sands (especially dunes) in the lowland zone; infrequent in coastal BC; N SE AK and S to N CA.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Poa douglasii subsp. macrantha (Vasey) D.D. Keck
Poa douglasii var. macrantha (Vasey) Boivin