(alpine bluegrass)
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Photo of Poa alpina by Carl Roland
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Poa alpina is a common grass occurring across Denali from boreal meadows on floodplains to high alpine slopes on both sides of the Alaska Range crest. This species occurs in a variety of moist habitats including meadows, mossy shrublands, open soil on slopes, alpine tundra and scree.
Poa alpina has broad blue-green leaves and a purplish
inflorescence. This perennial grass grows in tufts 10-40 cm tall. Plants have mainly basal leaves and 1-2 stem leaves. Leaves have persistent, white sheaths and are short, wide (2-5 mm), flat and abruptly pointed. The
inflorescence is an open panicle, oval or pyramidal, as wide as long, 1.5-8 cm long and greenish or purplish in color.
Spikelets have 3-6 bisexual flowers and are compressed. The
glumes are
ovate and broad, the second
glume somewhat longer than the first. The
lemmas are
ovate, pubescent on the
keel but have no basal cobwebs, and are
awn-less. The
anthers are 1.3-2.3 mm long. Fruits are single-seeded, indehiscent and dry.
Viviparous plants are occasionally seen. This species is similar to
Poa arctica, but in that species the
palea is hairy between nerves.
Poa alpina is perennial and flowers mid-summer in Denali.
Poa alpina is
monoecious, with
stamens and
pistils in the same florets (bisexual). Flowers are wind pollinated and seeds are gravity and wind disseminated.
viviparous plants are also occasionally seen.
Poa alpina is a widespread circumpolar species. In North America, P. alpina ranges from Alaska east throughout all Canadian provinces to Greenland, and southward through the Rocky Mountain states. In Alaska, P. alpina occurs scattered in suitable habitat state-wide, with the exception of the Aleutians. In Denali, P. alpina occurs widely in the mountains on both sides of the Alaska Range, extending into neighboring boreal areas along river corridors.
Details are shown in the Plots & Charts found at right, depicting recent Denali data.
Poa alpina is an alpine species that occurs at elevations from 187 m to 1625 m with an average plot elevation of 1016 m.
Details are shown in the Plots & Charts found at right. For more on how to interpret these figures, visit Understanding Data Presented.
Poa alpina grows in dry, rocky soils.
Wide-ranging; wet to well-drained, dry sites.