(glaucous bluegrass)
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Photo of Poa glauca by Carl Roland
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Poa glauca is a highly variable,
caespitose,
glaucous perennial grass that grows in a variety of well-drained, usually warm and sunny habits across Denali, most frequently in the mountains, or else in open soil of floodplains. This species has stiff stems, 15-25 cm tall. Leaves are flat or folded, 0.5-1 mm wide,
glaucous and shorter than the stem. The
ligules are membranous. The
inflorescence is a narrow panicle with stiff, short scabrous branches, 1-16 cm long.
Spikelets contain 3-5 bisexual florets, compressed.
Glumes are broadly
lanceolate.
Lemmas are scabrous, with
pubescence on the
keel, but lacking the cobwebby hairs at the base.
Anthers are 1.2-2.5 mm long. Fruits are single-seeded, indehiscent and dry. The long
anthers, lack of cobwebby hairs and scabrous
lemma are key characters for identifying this grass.
Poa glauca flowers mid-summer in Denali.
Poa glauca is
monoecious, with
stamens and
pistils in the same florets (bisexual). Flowers are wind pollinated. It is presumed to be
apomictic and readily hybridizes with other
Poa species. Seeds are gravity and wind dispersed.
In the broadest sense, Poa glauca is a polymorphic and widespread circumpolar species complex. In North America, P. glauca ranges from Alaska through all Canadian provinces and southward into the western U.S. states, Great Lakes states, and New England. Poa glauca occurs all across Alaska except is absent from the Aleutians and is quite rare in the southeastern panhandle. In Denali, Poa glauca occurs most commonly in the northeastern quadrant of the park but also widely throughout the mountains and floodplains on both sides of the Alaska Range.
Details are shown in the Plots & Charts found at right, depicting recent Denali data.
Poa glauca grows at elevations from 187 m to 1572 m with an average plot elevation of 979 m. This species shows no strong preference for site aspect. It is commonly found on steep sites, with an average plot slope of 19 degrees.
Details are shown in the Plots & Charts found at right. For more on how to interpret these figures, visit Understanding Data Presented.
Poa glauca is early successional pioneer species that grows in a variety of sandy to rocky habitats including: hummocks, snow beds, alpine tundra, river terraces, streambanks, animal burrows, ridges, slopes, and cliffs.
Well-drained dry to moist sites.
