(arctic bluegrass)Select an option below for more information on this species
Photo of Poa arctica by Carl Roland
is a common, highly variable rhizomatous
perennial grass that occurs widely across Denali from the lowlands to high alpine areas. This species occurs in a variety of habitats from muskeg
to sparsely vegetated alpine slopes. Plants are usually rhizomatous
with erect stems, 10-30 cm tall usually with 2 nodes
along the stem. Leaves are mostly basal, short, often narrow and thin; flat to involute
in cross-section. The ligules
are membranous. The inflorescence
is an open pyramidal panicle, the branches often flexuose
mainly have two bisexual flowers. The two glumes
are of equal length. The lemmas
are long-hairy between the nerves and have a basal tuft of cobwebby hairs present. Paleas
are hairy. Anthers
are longer than 1 mm. Fruits are single-seeded, indehiscent and dry. The long-hairy lemma
helps to distinguish this species from other Poa
species in the park.
Poa arctica is perennial and flowers mid-summer in Denali.
, with stamens
in the same florets (bisexual). Flowers are wind pollinated. Seeds are gravity and wind dispersed. viviparous
plants are sometimes encountered.
Poa arctica is a widespread and highly variable species complex with complex taxonomy and numerous subspecies. In the broad sense, Poa arctica has a circumpolar worldwide distribution. In North America, it ranges from Alaska, into all Canadian provinces, and south through the Rocky Mountain states to New Mexico, and west to Washington state. This species is common and widespread throughout Alaska. In Denali, it occurs widely in numerous habitats on both sides of the Alaska Range crest.
Details are shown in the Plots & Charts found at right, depicting recent Denali data.
Poa arctica is primarily an alpine species that grows from 134 m to 1742 m, with an average plot elevation of 1000 m. It does not show a strong affinity towards any aspect. It is commonly found on moderate to steep sites, with an average plot slope of 15 degrees.
Details are shown in the Plots & Charts found at right. For more on how to interpret these figures, visit Understanding Data Presented.
Wide-ranging; wet to well-drained, dry sites.
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