Poa glauca

Vahl
Treatment appears in FNA Volume 24. Treatment on page 576.

Plants perennial; usually glaucous; densely tufted, not stoloniferous, not rhizomatous. Basal branching all or mostly extravaginal. Culms 5-40 (80) cm, erect to spreading, straight, wiry, bases straight or slightly decumbent; nodes terete or slightly compressed, usually 0-1 exserted, top node at 1/10-1/3 the culm length. Sheaths closed for 1/10 – 1/5 their length, terete, bases of basal sheaths glabrous or sparsely minutely hairy, hairs 0.1-0.2 mm, distal sheath lengths 1.1-4 times blade lengths; ligules 1-4 (5) mm, sparsely to densely scabrous, apices obtuse to acute, minutely ciliolate; blades 0.8-2.5 mm wide, flat or folded, thin, soft, appressed or abruptly ascending to spreading, straight, apices narrowly prow-shaped. Panicles 1-10 (20) cm, lengths 3-5 times widths at maturity, rarely racemelike with branches of irregular length, erect, narrowly lanceoloid to ovoid, contracted to somewhat open, sparse, proximal internodes shorter than 1.5 (4) cm; nodes with 2-3 (5) branches; branches erect, ascending or weakly spreading, fairly straight, short, stout, angled, angles moderately to densely scabrous, rarely only scabrous distally, glaucous; pedicels usually shorter than the spikelets. Spikelets 3-7 (9) mm, lengths 2-3 times widths, laterally compressed, rarely bulbiferous, usually glaucous; florets 2-5, rarely bulb-forming; rachilla internodes to 1.2 mm, smooth, muriculate, or scabrous, glabrous or sparsely to densely hispidulous or puberulent. Glumes subequal, narrowly to broadly lanceolate, distinctly keeled, keels smooth or sparsely scabrous, apices acute; lower glumes 3-veined; upper glumes 2-3.8 (5.2) mm, lengths usually more than 4.1 times widths, distinctly shorter to subequal to the lowest lemmas; calluses glabrous or webbed, webs from minute to more than 1/2 the lemma length; lemmas 2.5-4 mm, lanceolate to broadly lanceolate, distinctly keeled, keels and marginal veins short-villous, lateral-veins obscure, usually sparsely softly puberulent to short-villous, intercostal regions smooth, sometimes weakly muriculate, glabrous or puberulent, margins glabrous, apices usually partially bronze-colored, obtuse or acute; palea keels scabrous, glabrous or softly puberulent at midlength, intercostal regions glabrous or softly puberulent; anthers (1) 1.2-2.5 mm, mature sacs 0.2 mm wide, rarely aborted late in development. 2n = 34, 42, 44, 47, 48, 49, 50, 56, 56, 57, 58, 60, 63, 64, 65, 70, 75, 78, ca. 100.

Distribution

Wash., Maine, N.H., Vt., Wis., Idaho, Oreg., Wyo., N.Mex., N.Y., Pa., Alaska, Nev., Colo., Calif., Ariz., Mich., Mont., Utah, Minn., Alta., B.C., Greenland, Man., N.B., Nfld. and Labr., N.S., N.W.T., Nunavut, Ont., Que., Sask., Yukon, S.Dak.

Discussion

Poa glauca is a common, highly variable, circumboreal, boreal forest to alpine and high arctic species. It grows from Alaska to Greenland, south to California and New Mexico in the west, and through Canada and the northeastern United States in the east. It also grows at scattered locations in Patagonia. It generally favors dry habitats and tolerates disturbance well. It can be distinguished from P. nemoralis (p. 574) and P. interior (see previous) by its longer ligules, lower top culm node, and wider glumes and lemmas. It can be difficult to distinguish from P. laxa subsp. banffiana (p. 570). Poa glauca is often confused in herbaria with P. abbreviata subsp. pattersonii (p. 582). It differs in having primarily extravaginal branching and, usually, longer anthers. It hybridizes with P. laxa, forming P. laxa x glauca (p. 572). It is also known to hybridize with P. hartzii (p. 589), and is suspected to hybridize with P. arctica (p. 529) and P. secunda (p. 586). It is highly polyploid, and presumed to be highly apomictic.

Selected References

None.

Key

1 All or some spikelets bulbiferous Poa glauca var. pekulnejensis
1 Spikelets not bulbiferous. > 2
2 Calluses usually webbed, sometimes glabrous; lemmas glabrous or hairy between the veins Poa glauca subsp. glauca
2 Calluses glabrous; lemmas hairy between the veins Poa glauca subsp. rupicola

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

... more about "Poa glauca"
100 +, 78 +, 75 +, 70 +, 65 +, 64 +, 63 +, 60 +, 58 +, 57 +, 56 +, 50 +, 49 +, 48 +, 47 +, 44 +, 42 +  and 34 +
membranous +  and scarious +
puberulent +, hispidulous +, hairy +  and glabrous +
1 cm10 mm <br />0.01 m <br /> (?) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
bronze-colored +
acute +, obtuse +  and prow--shaped +
Robert J. Soreng +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
keeled +  and rounded +
strigose +  and glabrous +
pseudopetiolate +  and branching +
straight +
intravaginal +, extravaginal +, branching +  and basal +
hairy +  and glabrous +
swelling +
straight +
not evident +
folded +  and flat +
spreading;ascending;erect +
hispidulous +, glabrous +, smooth or +  and sparsely densely scabrous +
0.4 cm4 mm <br />0.004 m <br /> (15 cm150 mm <br />0.15 m <br />) +
webbed +  and glabrous +
compressed +  and terete +
straight +
erect +  and spreading +
compressed +  and terete +
5 cm50 mm <br />0.05 m <br /> (40 cm400 mm <br />0.4 m <br />) +
not woody +
Wash. +, Maine +, N.H. +, Vt. +, Wis. +, Idaho +, Oreg. +, Wyo. +, N.Mex. +, N.Y. +, Pa. +, Alaska +, Nev. +, Colo. +, Calif. +, Ariz. +, Mich. +, Mont. +, Utah +, Minn. +, Alta. +, B.C. +, Greenland +, Man. +, N.B. +, Nfld. and Labr. +, N.S. +, N.W.T. +, Nunavut +, Ont. +, Que. +, Sask. +, Yukon +  and S.Dak. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
2 +  and 5 +
compressed +
reduced +
1-3(5)-veined +
shorter or longer +
subtending +
keeled +  and lanceolate +
subequal +
distributed +
uncinate +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
0 +  and 1/6 +
Oval (?) +  and Round (?) +
milky white +  and slightly greenish +
puberulent +  and glabrous +
short-villous +
usually sparsely softly puberulent +  and short-villous +
5(7-11)-veined +
hairy +, glabrous +  and chartaceous +
/2 +  and 1 +
muriculate +
keeled +, lanceolate +  and broadly lanceolate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
coriaceous-membranous +
erose +  and entire +
white +  and milky white or hyaline +
ciliolate +  and smooth +
lacerate +, truncate +  and acuminate +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
membranous +
inconspicuous +
lobed +  and lanceolate +
milky white +  and slightly greenish +
concealed +  and prominent +
0 +  and 1 +
compressed +  and terete +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
20 cm200 mm <br />0.2 m <br /> (?) +
narrowly lanceoloid +  and ovoid +
1 cm10 mm <br />0.01 m <br /> (10 cm100 mm <br />0.1 m <br />) +
dry +  and fleshy +
1.5 cm15 mm <br />0.015 m <br /> (?) +
glabrous or +  and sparsely densely hispidulous or puberulent +
many +, 1 +  and 100 +
compressed +
0.3 cm3 mm <br />0.003 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Poa glauca +
Poa sect. Stenopoa +
species +
membranous +
distinctly shorter +  and subequal +
0.2 cm2 mm <br />0.002 m <br /> (0.38 cm3.8 mm <br />0.0038 m <br />) +
parallel +  and converging +
branching +, not rhizomatous +  and not stoloniferous +
aquatic +  and terrestrial +