Poa glauca
Poa strictiramea
glaucous blue grass, timberline bluegrass, white bluegrass
Big Bend bluegrass
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.
30-90 cm, slender to coarse.
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.
closed for 1/20 – 1/10 their length, terete, scabrous, glabrous;
collars smooth to scabrous;
ligules 0.5-4(6) mm, scabrous, apices truncate to acute, entire or lacerate;
innovation blades 15-30 cm;
cauline blades 1-4 mm wide, involute or rarely flat, moderately thick and firm, both surfaces sparsely to densely antrorsely scabrous, apices narrowly prow-shaped, flag leaf blades usually longer than their sheaths.
all or mostly extravaginal.
intra-vaginal.
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.
(7)10-30 cm, erect, pyramidal, open, with 2-5 branches per node;
branches 2-8(15) cm, spreading, straight, angled, angles moderately to densely scabrous, sometimes densely scabrous all over, with 10-30 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.
4-7 mm, lanceolate, laterally compressed;
florets 2-5;
rachilla internodes 0.8-1.5 mm, smooth or scabrous, sometimes sparsely hispidulous.
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.
sparsely to rarely densely scabrous;
lower glumes 1-3-veined;
calluses usually glabrous, rarely sparsely short-webbed;
lemmas 2.5-3.5 mm, lanceolate, distinctly keeled, smooth or sparsely to densely scabrous, keels and marginal veins glabrous or softly puberulent or short- to long-villous, lateral veins moderately prominent to prominent, intercostal regions usually glabrous, infrequently sparsely softly puberulent, apices acute;
palea keels scabrous;
anthers aborted late in development, or 2.2-2.5 mm.
= 34, 42, 44, 47, 48, 49, 50, 56, 56, 57, 58, 60, 63, 64, 65, 70, 75, 78, ca. 100.
= 28+1, 28-29+11.
Poa glauca
Poa strictiramea
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.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Poa strictiramea grows on shady, upland mountain slopes, usually below north-facing cliffs, in and around the Chihuahuan Desert. In the United States, it is known only from the Chisos Mountains, Texas. It used to be treated as P. involuta Hitchc. Plants from the eastern part of its range, including the Chisos Mountains, commonly have short, truncate ligules, whereas westward in Mexico, plants with long, acute ligules are more common.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. All or some spikelets bulbiferous | var. pekulnejensis |
1. Spikelets not bulbiferous. | → 2 |
2. Calluses usually webbed, sometimes glabrous; lemmas glabrous or hairy between the veins | subsp. glauca |
2. Calluses glabrous; lemmas hairy between the veins | subsp. rupicola |
BC
OR
WA
CalFlora
Flora NW
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MI Flora
MN Wildflowers
PNW Herbaria
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