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

Poa glauca Vahl
glaucous bluegrass (timberline bluegrass)
Poaceae (Grass family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #17170)

E-Flora BC Static Map
Distribution of Poa glauca
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Species Information

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PMPOA4Z0Z1
PMPOA4Z0Z3


General:
Perennial, densely tufted grass from fibrous roots; stems erect to spreading, stiff, wiry, straight or slightly decumbent, 5-40 cm tall, usually with 0 or 1 node exserted, uppermost node usually in lowermost 1/3 of stem.
Leaves:
Sheath margins open 4/5-9/10 their length, top stem sheath 3-10 cm long; sterile shoots all or most flowering within a season, next year's shoots set late in the growing season, mostly breaking through sheath bases with indistinct two-keeled buds protecting the scales; basal bladeless leaves present; blades 0.8-2.5 mm wide, mostly flat, appressed or abruptly ascending to spreading, stiff, soon withering; top stem blades usually distinctly shorter than their sheaths (length ratio mostly 0.25-11); ligules 1-4 (5) mm long, the tips rounded to sharp-pointed, minutely rough, the backs more or less finely rough.
Flowers:
Inflorescence an erect panicle, 1-10 cm long, narrowly lanceolate to egg-shaped, contracted or open, sparingly branched and flowered, lowermost internodes less than 1 cm long (rarely more), the primary branches 2 to 3 (5) per node, ascending to spreading, stout, moderately to distinctly rough on angles (rarely nearly smooth), the stalks long-exserted, the spikelet stalks mostly shorter than spikelets; spikelets laterally compressed, 3-8 mm long, (2-) 3- to 5-flowered; glumes narrowly to broadly lanceolate, the keels distinct, the lower ones 3-nerved; rachilla internodes mostly less than 1 mm long, smooth, minutely bumpy, or rough, or hairless or frequently sparsely short straight-haired to moderately minutely soft-hairy; lemmas lanceolate to broadly lanceolate, keeled, 2.5-4 mm long, the tips usually bronze-coloured in part, sharp-pointed, keels and marginal nerves short silky-hairy, lateral nerves usually short silky-hairy or sparsely minutely soft-hairy, between nerves hairless or minutely crisp- to soft-hairy; calluses hairless or cobwebby, often minutely so; palea keels rough, hairless or medially minutely soft-hairy; flowers bisexual (some appearing female-like due to aborted anthers); anthers (1) 1.2-2.5 mm long, well-developed or infrequently aborted late in development.
Notes:
Two subspecies occur in BC:

1. Lemmas short-hairy between the nerves; calluses of all florets entirely hairless; dwarf alpine plants.................... ssp. rupicola (Nash) W.A. Weber

1. Lemmas variously short-hairy or hairy; calluses webbed or not; if dwarf alpine plants, then calluses of at least the basal florets within a spikelet with at least a vestige of a web or the lemmas smooth between the nerves.................... ssp. glauca

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Purple
Blooming Period:
Mid Summer
Fruit/Seed characteristics:
Colour: Brown
Present over the
Source:  The USDA

Habitat / Range

Dry ridges, grassy slopes, stony meadows and mossy ledges in the montane to alpine zones; common throughout BC; ssp. glauca - circumpolar, N to AK, YT and NT, E to NF and S to ME, WI, MN, NM, UT, ID and OR; Iceland, Eurasia; ssp. rupicola - N to YT, E to MB and S to SD, NM, AZ and CA.

Source: The Illustrated Flora of British Columbia

Ecology

Ecological Framework for Poa glauca

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) 6 1653 2854
Slope Gradient (%) 0 37 130
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
5 198 350
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 2 7
Modal Nutrient Regime
Class
C
Number of field plots
 species was recorded in:
221
Modal BEC Zone Class
ESSF
All BEC Zones (# of stations/zone) species was recorded in: AT(26), BAFA(33), BWBS(12), CWH(1), ESSF(70), ICH(4), IDF(17), IMA(6), MS(4), PP(2), SBPS(1), SBS(30), SWB(11)

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 balfourii Parn.

Taxonomic and Nomenclatural Links

Additional Photo Sources

Related Databases

General References