Poa bolanderi |
Poa laxiflora |
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Bolander's blue grass |
lax-flower bluegrass, loose-flower blue grass |
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Habit | Plants usually annual, rarely longer-lived; often glaucous; densely tufted, tuft bases narrow, sterile shoots few, not stoloniferous, not rhizomatous. | Plants perennial; green throughout; loosely tufted or with solitary shoots, long-rhizomatous. |
Culms | 20-60(70) cm, erect or geniculate at the base; nodes terete, usually 1-3 exserted. |
50-120 cm. |
Sheaths | closed for 1/2-1/4 their length, usually compressed and keeled, usually smooth, infrequently scabrous; ligules 2.5-7 mm, smooth or scabrous, usually decurrent, obtuse to acute; blades 1.5-5 mm wide, usually flat, rarely folded, lax, soft, smooth or sparsely scabrous, margins scabrous, apices broadly prow-shaped, cauline blades 3-15 cm, flag leaf blades 1-4 cm. |
closed for 1/2 - 3/4 their length, usually sparsely to moderately retrorsely scabrous, margins not ciliate; ligules 2-3.5 mm, smooth or sparsely scabrous, obtuse to acute; blades 3-8 mm wide, flat, lax, apices narrowly prow-shaped. |
Basal branching | both intra- and extravaginal. |
extravaginal. |
Panicles | (5)10-15(25) cm long, 1/4-1/2 the plant height, usually erect, infrequently slightly nodding, usually eventually open, sometimes interrupted, sparse, with 1-3(5) branches per node; branches initially erect and straight, usually some eventually spreading or reflexed, smooth or sparsely to moderately scabrous. |
14-30 cm, open, sparse, with 1-3(4) branches per node; branches (5.5)8-12(15) cm, widely spreading, fairly straight, angled, angles sparsely to moderately scabrous, with 3-13 spikelets. |
Spikelets | (3)4-7 mm, laterally compressed; florets 2-3(4); rachilla internodes usually 1-1.2+ mm, smooth or sparsely scabrous, glabrous. |
4-8 mm, laterally compressed, rarely bulbiferous; florets 2-4, usually normal, rarely bulb-forming; rachilla internodes about 1 mm, smooth, glabrous. |
Glumes | unequal, distinctly shorter than the adjacent lemmas, distinctly keeled, keels smooth or sparsely scabrous; lower glumes 1-3-veined, 1/2 - 2/3 the length of the upper glume, 1/2 - 2/3 the length of the lowest lemmas; upper glumes shorter than or subequal to the lowest lemmas; calluses of some or all florets sparsely webbed; lemmas 2.5-4 mm, lanceolate to narrowly lanceolate, distinctly keeled, smooth or scabrous throughout, glabrous, lateral veins obscure to moderately prominent, apices narrowly acute, usually anthocyanic near the tip; palea keels sparsely scabrous; anthers 3, 0.5-1(1.8) mm. |
distinctly keeled, keels scabrous; lower glumes lanceolate, 1-3-veined; upper glumes shorter than or subequal to the lowest lemmas; calluses webbed; lemmas 3.2-6 mm, lanceolate, distinctly keeled, smooth or sparsely finely scabrous, keels and marginal veins long-villous, keels hairy to 2/3 – 3/4 their length, marginal veins sparsely hairy, lateral veins moderately prominent, usually glabrous, rarely sparsely softly puberulent, intercostal regions glabrous, apices acute; paleas scabrous, glabrous over the keels; anthers 0.5-1.1 mm. |
2n | = 28. |
= ca. 98. |
Poa bolanderi |
Poa laxiflora |
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Distribution |
CA; ID; NV; OR; UT; WA; BC
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AK; OR; WA; BC |
Discussion | Poa bolanderi grows mainly in pine to fir forest openings of mountain slopes in the western United States, from Washington to California and Utah. It differs from P. howellii (see below) in having smooth to scabrous, rather than puberulent, lemmas; it also grows at higher elevations, mostly at 1500-3000 m. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Poa laxiflora is restricted to mesic, old growth, mixed conifer forests of the Pacific coast, from Alaska south through the western foothills of the northern Cascades to Oregon. It is not a common species. A bulbiferous specimen was collected in the Queen Charlotte Islands. Inclusion of Poa laxiflora in Poa sect. Homalopoa is tentative; it may belong to sect. Sylvestres. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 533. | FNA vol. 24, p. 538. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Homalopoa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Homalopoa |
Sibling taxa | ||
Synonyms | P. howellii var. chandleri | |
Name authority | Vasey | Buckley |
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