Canada Bluegrass - Poa compressa
Rhizomatous perennial. Stems 20–50 dm, wiry and flattened, nodes often distinctly bent and banded with contrasting lighter and darker bands. Leaves: blades 1.5–4 mm wide, from stem, rarely basal; ligules 1–3 mm long. Inflorescence a narrow panicle 2–8 cm long. Spikelets 3–6 mm long. Lemmas with cobwebby hairs at very base (Lavin in Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
The genus Poa is distinguished by its flat leaf blades, 2-6 flowered panicles, 1-3 nerved glumes, and 5-nerved lemmas (Gleason 1957, Mohlenbrock 1972, Hitchcock 1950). Some species have a tuft of cobwebby hairs at the base.
Poa compressa is visually separated from Poa pratensis by its blue-green foliage, distinctly flat culms and narrow compact inflorescence (Gleason and Cronquist 1953, USDA 1948). Bases of the strongly keeled lemmas are less conspicuously cobwebby than on Poa pratensis (Gleason and Cronquist 1953).
Despite its common name, Canada bluegrass (Poa compressa) is undisputedly considered to be a European introduction (Hitchcock 1950, USDA 1948, Fernald 1950, Gleason and Cronquist 1953).
Introduced throughout most of North America (Lavin in Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
Roadside, road cuts, trailside, along ditches, and on open slopes and other open site with a combination of moisture and regular moderate disturbance (Lavin in Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
- Additional ReferencesLegend: View Online Publication
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- Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.