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

Poa annua L.
annual bluegrass
Poaceae (Grass family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #6575)

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Distribution of Poa annua
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Species Information

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General:
Annual tufted grass (rarely longer-lived), from fibrous roots, sometimes from stolons; stems 2-20 (45) cm tall.
Leaves:
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.
Flowers:
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.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Yellow
Blooming Period:
Mid Spring
Fruit/Seed characteristics:
Colour: Brown
Present from Spring to Summer
Source:  The USDA

Habitat / 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.

Source: The Illustrated Flora of British Columbia

Ecology

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

Minimum

Average

Maximum

Elevation (metres) 3 702 1580
Slope Gradient (%) 0 27 78
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
45 168 244
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
2 3 6
Modal Nutrient Regime
Class
B
Number of field plots
 species was recorded in:
8
Modal BEC Zone Class
BWBS
All BEC Zones (# of stations/zone) species was recorded in: BWBS(3), CWH(1), MS(1), SBS(1)

Climate

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

Poa annua var. aquatica Asch.
Poa annua var. reptans Hausskn.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References