Poa howellii |
Poa bolanderi |
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Howell's blue grass |
Bolander's blue grass |
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Habit | Plants usually annual, rarely longer-lived; densely tufted, tuft bases narrow; not stoloniferous, not rhizomatous. | Plants usually annual, rarely longer-lived; often glaucous; densely tufted, tuft bases narrow, sterile shoots few, not stoloniferous, not rhizomatous. |
Culms | (10) 25-80(120) cm tall, 0.4-1.75 mm thick, usually erect; nodes terete, usually 1-2 exserted. |
20-60(70) cm, erect or geniculate at the base; nodes terete, usually 1-3 exserted. |
Sheaths | closed for 1/2 - 7/8 their length, usually weakly compressed and keeled, usually scabrous, rarely smooth; ligules 1.5-5(10) mm, smooth or scabrous, acute; blades 1-7(10) mm wide, flat, lax, soft, finely scabrous, apices narrowly prow-shaped, cauline blades 2-10 cm. |
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. |
Basal branching | intravaginal. |
both intra- and extravaginal. |
Panicles | 10-25(30) cm, erect, eventually open, with (1)3-5(7) branches per node; branches eventually spreading or reflexed, fairly straight, angled, angles usually moderately to densely scabrous, rarely sparsely scabrous. |
(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. |
Spikelets | (2)4-6 mm, laterally compressed, with 2-5 florets; rachilla internodes about 1 mm, smooth, usually softly puberulent, infrequently glabrous. |
(3)4-7 mm, laterally compressed; florets 2-3(4); rachilla internodes usually 1-1.2+ mm, smooth or sparsely scabrous, glabrous. |
Glumes | slightly unequal, lanceolate, distinctly keeled, keels and sometimes the lateral veins sparsely to moderately scabrous; lower glumes 1-3-veined; upper glumes shorter than or subequal to the lowest lemmas; calluses of some or all florets sparsely webbed; lemmas 2.5-3.5 mm, lanceolate to narrowly lanceolate, distinctly keeled, crisply puberulent proximally, hairs evenly distributed, finely scabrous distally, lateral veins obscure to prominent, margins narrowly hyaline, glabrous, apices narrowly acute, infrequently anthocyanic; palea keels sparsely scabrous, glabrous or softly puberulent at midlength, intercostal regions usually softly puberulent; anthers 3, 0.2-1 mm. |
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. |
2n | = unknown. |
= 28. |
Poa howellii |
Poa bolanderi |
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Distribution |
CA; OR; WA; BC
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CA; ID; NV; OR; UT; WA; BC
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Discussion | Poa howellii grows primarily on rocky banks and wooded slopes, from the coastal ranges of southern British Columbia to southern California. It differs from P. bolanderi (see above) in having puberulent, rather than smooth or scabrous, lemmas, and in growing at lower elevations, mostly from near sea level to 1000 m. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 24, p. 534. | FNA vol. 24, p. 533. |
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. bolanderi var. howellii | P. howellii var. chandleri |
Name authority | Vasey & Scribn. | Vasey |
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