Poa nemoralis L.
wood bluegrass (interior bluegrass (ssp. interior); woods bluegrass (ssp. nemoralis))
Poaceae (Grass family)

Introduction to Vascular Plants

Photograph

© Jamie Fenneman     (Photo ID #11522)


Map

E-Flora BC Static Map

Distribution of Poa nemoralis
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Species Information

General:
Perennial, tufted grass from fibrous roots, green or glaucous; stems mostly erect or ascending, 5-80 cm tall, 0 to 5 nodes exserted, uppermost node usually in the middle to upper 1/3 of stem.
Leaves:
Sheath margins open 4/5-9/10 their length; sterile shoots all or most flowering within a season, next year's shoots set late in the growing season, all or most breaking through sheath bases with indistinct two-keeled buds protecting the scales; basal leaves bladeless; blades 0.8-3 mm wide, mostly flat, appressed or abruptly ascending to spreading, strict or somewhat lax; ligules 0.2-3 mm long, the tips blunt to rounded, minutely rough, the backs distinctly rough.
Flowers:
Inflorescence an erect or lax panicle, 4-20 cm long, narrowly lanceolate to egg-shaped, sparsely to moderately congested, the branches 2 to 5 per node, ascending to widely spreading, slender, moderately to distinctly rough on angles, the stalks shortly exserted; spikelets laterally compressed, 3-8 mm long, (1) 2- to 5-flowered; glumes awl-like to lanceolate, the lower ones 3-nerved; rachilla internodes mostly less than 1 mm long, smooth or rough, hairless or minutely soft-hairy; lemmas narrowly lanceolate to lanceolate, 2.4-4 mm long, the tips usually bronze-coloured in part, sharp-pointed, the keels and marginal nerves short silky-hairy, hairless or infrequently sparsely and minutely soft-hairy between the nerves; calluses sparsely and often short-cobwebby (rarely hairless); palea keels rough; flowers bisexual (some appearing female-like due to aborted anthers); anthers (0.8) 1.2-2.5 mm long.
Notes:
Two subspecies occur in BC:

1. Uppermost culm nodes located on the upper 2/3 of the culms, 2-4 nodes exposed at maturity; ligules less than 0.8 (1) mm long; culms not rough below the panicles; lowest glumes awl-like to narrowly lanceolate, nearly equaling the lowest lemmas in length.................... ssp. nemoralis

1. Uppermost culm nodes located on the lower 1/2 of the culms (sometimes higher), 0-2 (3) nodes exposed at maturity; ligules more than (0.8) 1 mm long; culms sometimes rough below the panicles; lowest glumes narrowly to broadly lanceolate, 3/4 or less the length of the lowest lemmas.................... ssp. interior (Rydb.) W. A. Weber

SourceThe Illustrated Flora of British Columbia

Ecology

Ecological Framework for Poa nemoralis

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

Avg

Min

Max

Elevation (metres)
1165 250 2500
Slope Gradient (%)
22 0 97

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

218 0 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
3 1 7
Modal Nutrient Regime
Class
D
# of field plots
 species was recorded in:
77
Modal BEC Zone Class
IDF

All BEC Zones (# of stations/zone) species was recorded in

BG(1), BWBS(4), CWH(1), ESSF(18), ICH(1), IDF(18), IMA(1), MS(7), SBPS(2), SBS(18)

Habitat and Range

Dry to mesic meadows, rocky slopes and open forests in the montane zone (ssp. interior); moist forests and disturbed sites in the lowland zone (ssp. nemoralis); frequent E of the Coast-Cascade Mountains (ssp. interior), infrequent in SW BC (ssp. nemoralis); N to AK, YT and NT, E to PQ and S to VT, IL, MO, TX, NM, ID and WA (ssp. interior), introduced from Eurasia (ssp. nemoralis).

SourceThe Illustrated Flora of British Columbia

Synonyms

Synonyms and Alternate Names:
Poa interior Rydb.
Poa nemoralis var. interior (Rydb.) Butters & Abbe