Poa howellii |
Poa saltuensis |
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Howell's blue grass |
old-pasture blue grass |
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Habit | Plants usually annual, rarely longer-lived; densely tufted, tuft bases narrow; not stoloniferous, not rhizomatous. | Plants perennial; not rhizomatous, not stoloniferous, loosely tufted. | ||||
Culms | (10) 25-80(120) cm tall, 0.4-1.75 mm thick, usually erect; nodes terete, usually 1-2 exserted. |
20-95 cm tall, 0.8-1.5 mm thick. |
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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 1/3-2/3 their length; ligules 0.2-3(4) mm, smooth or sparsely scabrous, truncate to obtuse; blades 1-3.6 (6) mm wide, flat, thin, lax, veins prominent. |
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Basal branching | intravaginal. |
mainly pseudointravaginal. |
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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. |
4-20(24) cm long, less than 1/4 the plant height, lax; nodes with 1-3 branches; branches ascending to spreading, lax, angled, angles prominent, scabrous. |
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Spikelets | (2)4-6 mm, laterally compressed, with 2-5 florets; rachilla internodes about 1 mm, smooth, usually softly puberulent, infrequently glabrous. |
3-5.6 mm, laterally compressed; florets 2-5; rachilla internodes glabrous, usually shorter than 1 mm. |
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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. |
2/3 – 3/4 as long as the adjacent lemmas, distinctly keeled; lower glumes 1(3)-veined; upper glumes shorter than or subequal to the lowest lemmas; calluses webbed; lemmas 2.4-4 mm, lanceolate to broadly lanceolate, distinctly keeled, usually glabrous, bases of marginal veins rarely sparsely softly puberulent, lateral veins prominent, intercostal regions smooth, minutely bumpy, apices obtuse to sharply acute or acuminate; palea keels scabrous; anthers 0.4-1.5 mm. |
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2n | = unknown. |
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Poa howellii |
Poa saltuensis |
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Distribution |
CA; OR; WA; BC
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CT; IA; IL; IN; KY; MA; MD; ME; MI; MN; NC; NH; NJ; NY; OH; PA; RI; TN; VA; VT; WI; WV; LB; NB; NS; ON; PE; QC
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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 saltuensis grows in woodlands of the north-central and northeastern United States and adjacent Canada, extending south to Tennessee. The two subspecies are sometimes treated as species. The variation between the two overlaps and is correlated to some extent with ecology and geography. Poa marcida (p. 512), a western species once included in P. saltuensis, differs in having closed sheaths and attenuate lemmas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 24, p. 534. | FNA vol. 24, p. 510. | ||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Homalopoa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Sylvestres | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | P. bolanderi var. howellii | P. saltuensis var. microlepis, P. languida | ||||
Name authority | Vasey & Scribn. | Fernald & Wiegand | ||||
Web links |
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