Poa annua L.
annual bluegrass
Poaceae (Grass family)

Introduction to Vascular Plants


© Jamie Fenneman     (Photo ID #6575)


E-Flora BC Static Map

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

Species Information

Annual tufted grass (rarely longer-lived), from fibrous roots, sometimes from stolons; stems 2-20 (45) cm tall.
Sheath margins open about 2/3 their length; sterile shoots emerging inside sheaths with indistinct, two-keeled buds protecting the scales; blades 1-3 mm wide, flat, thin; ligules 0.5-3 mm long, the backs smooth, hairless.
Inflorescence an erect panicle, 1-10 cm long, 1.2-1.6 times longer than wide, the branches 1 to 2 (3) per node, ascending to spreading or reflexed; spikelets laterally compressed, 3-5 mm long, 2- to 6-flowered; lower glumes 1-nerved; rachillas smooth, hairless, more or less concealed, terminal internodes less than 1/2 (3/4) length of terminal lemmas; lemmas lanceolate, 2.5-4 mm long, the tips rounded to sharp-pointed, surface smooth, keel, marginal, and often lateral nerves silky- to minutely crisply- or soft-hairy (rarely hairless throughout), lateral nerves moderately prominent; calluses hairless; palea keels silky-hairy; flowers bisexual, or the upper ones in a spikelet female; anthers 0.6-1.1 mm long, cylindrical prior to opening.

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 from Spring to Summer
Source:  The USDA


Ecological Framework for Poa annua

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)
702 3 1580
Slope Gradient (%)
27 0 78

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

168 45 244
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
3 2 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

BWBS(3), CWH(1), MS(1), SBS(1)

Habitat and Range

Dry to moist waste areas, lawns and gardens in the lowland and montane zones; common throughout BC, especially S and W BC; introduced from Eurasia.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Poa annua var. aquatica Asch.
Poa annua var. reptans Hausskn.