Poa glauca Vahl
glaucous bluegrass (timberline bluegrass)
Poaceae (Grass family)
Introduction to Vascular Plants
glaucous bluegrass (timberline bluegrass)
Poaceae (Grass family)
Introduction to Vascular Plants
Species Information click to expand contents
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
USDA Species Characteristics click to expand contents
Flower Colour:
Purple
Blooming Period:
Mid Summer
Fruit/Seed characteristics:
Colour: Brown
Present over the
Source: The USDA
Ecology click to expand contents
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)
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) |
1653 | 6 | 2854 |
Slope
Gradient (%) |
37 | 0 | 130 |
Aspect (degrees) |
198 | 5 | 350 |
Soil
Moisture Regime (SMR) [0 - very xeric; 4 - mesic; 8 - hydric] |
2 | 0 | 7 |
Modal
Nutrient Regime
Class |
C | ||
#
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) | ||
Source:
Klinkenberg 2013
|
Habitat and Range click to expand contents
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.
Synonyms click to expand contents
Synonyms and Alternate Names:
Poa balfourii Parn.