Plants perennial; not glaucous; densely cespitose, not rhizomatous, not stoloniferous. Basal branching intravaginal. Culms 10-40 cm. Leaves mostly basal; sheaths closed for 1/8 – 2/7 their length, terete, basal sheaths persistent, overlapping, bases usually not swollen; ligules of innovations 1-2 (3) mm, those of the upper cauline leaves to 4 (5) mm, milky white, smooth, glabrous, obtuse; blades of innovations widely spreading, persisting through the season, blades of cauline leaves 1-5 (12) cm long, 2-4.5 mm wide, flat, moderately thick, soft, straight, smooth or the margins sparsely scabrous, apices broadly prow-shaped, blades of upper cauline leaves much reduced in length. Panicles 2-6 (8) cm, erect, ovoid to pyramidal, open or loosely contracted at maturity, fairly congested; nodes with 1-2 branches, lowest internodes 0.6-1 (1.5) cm; branches 1-3 (4) cm, ascending to spreading, straight, terete, usually smooth or sparsely scabrous, rarely moderately densely scabrous; pedicels divaricate, shorter than the spikelets. Spikelets 3.9-6.2 mm, ovate, lengths 1.5-2.5 times widths, laterally compressed, plump, sometimes bulbiferous; florets 3-7, usually normal; rachilla internodes 0.5-0.8 mm, smooth, glabrous or sparsely softly puberulent to short-villous. Glumes broadly lanceolate to narrowly ovate, keeled, keels sparsely scabrous; lower glumes 3-veined; upper glumes shorter than or subequal to the lowest lemmas; calluses glabrous; lemmas 3-5 mm, broadly lanceolate, keeled, keels and marginal veins short to long-villous, lateral-veins moderately prominent, intercostal regions sparsely to moderately short-villous, apices acute; palea keels softly puberulent to short-villous over most of their length, apices scabrous; anthers 1.3-2.3 mm. 2n = 22, 23, 24,25, 26, 27, 28, 28+11, 30, 31, 32, 32+1, 33, 34, 35, 36, 37, 39, 40+1, 41, 42, ca. 43, 44, 46, ca. 48, 56.

Distribution

Colo., N.Mex., Wash., Utah, Alaska, Mich., Oreg., Mont., Alta., B.C., Greenland, Man., N.B., Nfld. and Labr., N.S., N.W.T., Nunavut, Ont., Que., Sask., Yukon, Wyo., Idaho, Nev.

Discussion

Poa alpina is a fairly common circumboreal forest species of subalpine to arctic habitats, extending south in the Rocky Mountains to Utah and Colorado in the west, and to the northern Great Lakes region in the east. It often grows in disturbed ground and is calciphilic. Poa xgaspensis (p. 601) is a natural hybrid which seems to be between P. alpina and P. pratensis subsp. alpigena (p. 525); it differs from P. alpina in its extravaginal branching, rhizomatous habit, and webbed calluses. The range of chromosome numbers suggests that P. alpina is predominantly apomictic.

Selected References

None.

Key

1 Spikelets not bulbiferous Poa alpina subsp. alpina
1 Some or all spikelets bulbiferous Poa alpina subsp. vivipara

No values specified."decumbent" is not a number.

... more about "Poa alpina"
56 +, 48 +, 46 +, 44 +, 43 +, 42 +, 41 +, 1 +, 39 +, 37 +, 36 +, 35 +, 34 +, 33 +, 32 +, 31 +, 30 +, 11 +, 28 +, 27 +, 26 +, 25 +, 24 +, 23 +  and 22 +
membranous +  and scarious +
puberulent +, hispidulous +, hairy +  and glabrous +
5 cm50 mm <br />0.05 m <br /> (?) +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
scarious-hyaline +
Robert J. Soreng +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
keeled +  and rounded +
strigose +  and glabrous +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swollen +
swelling +
straight +
not evident +
involute +, folded +  and flat +
thick;2mm;4.5mm +
4 cm40 mm <br />0.04 m <br /> (?) +
ascending;spreading +
hispidulous +, glabrous +, smooth or +  and sparsely densely scabrous +
unbranched +  and hollow +
ascending +  and erect +
10 cm100 mm <br />0.1 m <br /> (40 cm400 mm <br />0.4 m <br />) +
not woody +
Colo. +, N.Mex. +, Wash. +, Utah +, Alaska +, Mich. +, Oreg. +, Mont. +, Alta. +, B.C. +, Greenland +, Man. +, N.B. +, Nfld. and Labr. +, N.S. +, N.W.T. +, Nunavut +, Ont. +, Que. +, Sask. +, Yukon +, Wyo. +, Idaho +  and Nev. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
3 +  and 7 +
compressed +
reduced +
1-3(5)-veined +
shorter or longer +
subtending +
keeled +, broadly lanceolate +  and narrowly ovate +
subequal +
distributed +
uncinate +
0.1 cm1 mm <br />0.001 m <br /> (?) +
0 +  and 1/6 +
Oval (?) +  and Round (?) +
milky white +  and slightly greenish +
long-villous +
5(7-11)-veined +
hairy +, glabrous +  and chartaceous +
keeled +  and lanceolate +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
membranous +
erose +  and entire +
white +  and milky white or hyaline +
ciliolate +  and smooth +
lacerate +, truncate +  and acuminate +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
membranous +
inconspicuous +
lobed +  and lanceolate +
milky white +  and slightly greenish +
glabrous +, scabrous +  and smooth +
concealed +  and prominent +
0 +  and 5 +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
8 cm80 mm <br />0.08 m <br /> (?) +
ovoid +  and pyramidal +
2 cm20 mm <br />0.02 m <br /> (6 cm60 mm <br />0.06 m <br />) +
dry +  and fleshy +
sparsely softly puberulent +  and short-villous +
many +, 1 +  and 100 +
compressed +  and ovate +
0.39 cm3.9 mm <br />0.0039 m <br /> (0.62 cm6.2 mm <br />0.0062 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Poa alpina +
Poa sect. Alpinae +
species +
membranous +
parallel +  and converging +
branching +, not stoloniferous +  and not rhizomatous +
plant +  and cespitose +
aquatic +  and terrestrial +