Poa alpina L.
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TAXONOMY
 
Family: Poaceae
Genus: Poa
 
Species Synonyms: Poa alpina ssp. vivipara (L.) Arcang.
Poa vivipara (L.) Willd.
Common Names: alpine bluegrass
 
DISTRIBUTION
 
Canada: Yukon – Mackenzie District – Keewatin – Ungava – Baffin Island – Labrador, south to British Columbia – Alberta – northern Saskatchewan – Manitoba, Ontario – Newfoundland – Nova Scotia
Saskatchewan: northern Saskatchewan; Lake Athabasca – Hasbala Lake
Ecoregion: Tazin Lake Upland, Selwyn Lake Upland
 
HABITAT
 
Saskatchewan: rock outcrops, bouldery tundra, and gravel shores
Associated Species: poplar, white spruce
 
RARITY STATUS
 
Provincial Status According
to Harms (2003):
Endangered
Nature Conservancy Status:
G5 S1
Saskatchewan Species at
Risk Status:
None
COSEWIC Status:
None
 
Alpine bluegrass is endangered because it is rare in Saskatchewan and is restricted to one general region of the province. No threats are known or anticipated.
 
SPECIES DESCRIPTION
 
Height: 10 – 40 cm
Roots: fibrous
Stems: perennial, densely tufted, erect
Leaves: blades widely spreading, 1 or 2 on the stem, 1 – 5 cm long, 2 – 6 mm wide, reduced in length upwards flat, hairless or rough-hairy on margins
Inflorescence: 2 – 6 cm long, erect, pyramidal, open to loosely contracted, nodes with 1 – 2 branches, branches ascending to spreading
Spikelets: 4 – 6 mm long, laterally compressed, occasionally with sterile spikelets replacing fertile, containing up to five florets, purplish or bronze
Florets: glumes lance-shaped to oval, boat-shaped, ridges rough-hairy, at least the lower ones 3-veined; lemmas 3 – 5 mm long, lance-shaped, boat-shaped; paleas boat-shaped, ridge short to long-hairy
Fruits: grain
 
POA KEY FOR SPECIES FOUND IN SASKATCHEWAN
 
1 Spikelets not compressed; lemmas rounded on back, ridge obscure
P. secunda
1 Spikelets compressed laterally; lemmas boat-shaped, with a distinct ridge
2
   
2 Plants tufted, generally lacking rhizomes
3
2 Plants with distinct rhizomes
9
 
3 Lemmas with cobwebby hairs at base
4
3 Lemmas without cobwebby hairs at base
6
 
4 Lemmas hairy between the veins
P. glauca ssp. glauca
4 Lemmas hairless between the veins
5
 
5 Spikelets bronze at tip, relatively dark; inflorescence 13 – 30 cm long; lemma margins distinctly inrolled
P. palustris
5 Spikelets pale; inflorescence 3 – 15 cm long; lemma margins only slightly inrolled if at all
P. interior
 
6 Lemmas hairless (except for cobwebby hairs at base); leaves thread-like
P. cusickii
6 Lemmas hairy, at least on veins; leaves 1 – 6 mm wide
7
 
7 Annual, often rooting at the lower nodes; lemma distinctly 5-nerved
P. annua
7 Perennial; lemma with obscure intermediate nerves
8
 
8 Leaves 3 – 6 mm broad
P. alpina
8 Leaves 1 – 3 mm broad
P. glauca ssp. rupicola
 
9 Lemmas without cobwebby hairs at base
10
9 Lemmas with cobwebby hairs at base
11
 
10 Stems solitary or few, strongly flattened
P. compressa
10 Stems tufted, round or slightly flattened
P. arida
 
11 Lemmas greater than 4 mm long, profusely cobwebbed; inflorescence purplish, violet or greyish; stem leaves usually 1
12
11 Lemmas less than 4 mm long, cobwebby at base only; inflorescence green; stem leaves usually 2 or more
13
 
12 Ligules ca. 4 mm long; spikelets purplish-grey or brownish
P. arctica ssp. lanata
12 Ligules less than 2 mm long; spikelets purplish or greenish
P. arctica ssp. arctica
 
13 Basal leaves to 3 mm wide
P. pratensis ssp. pratensis
13 Basal leaves thread-like or inrolled
P. pratensis ssp. alpigena