Poa saltuensis |
Poa tracyi |
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old-pasture blue grass |
Tracy's bluegrass |
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Habit | Plants perennial; not rhizomatous, not stoloniferous, loosely tufted. | Plants perennial; loosely tufted, shortly rhizomatous. | ||||
Culms | 20-95 cm tall, 0.8-1.5 mm thick. |
(25)32-125 cm, erect or the bases decumbent, not branching above the base, terete or weakly compressed; nodes terete or slightly compressed, 1-2(3) exserted. |
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Sheaths | 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. |
closed for (2/5)1/2 – 9/10 their length, compressed, distinctly keeled, keels winged, wing to 0.5 mm wide, smooth or sparsely to infrequently densely scabrous, glabrous or infrequently retrorsely pubescent, bases of basal sheaths glabrous, distal sheath lengths 0.7-1.6 times blade lengths; collars with vestiture similar to the sheaths; ligules 2-4.5 mm, smooth or scabrous, glabrous or softly puberulent, obtuse to acute; innovation blades similar to the cauline blades; cauline blades (1.5)2-5.5 mm wide, flat, lax, smooth or sparsely scabrous mainly over the veins, apices broadly prow-shaped, flag leaf blades 6-20 cm. |
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Basal branching | mainly pseudointravaginal. |
mainly extravaginal. |
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Panicles | 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. |
(8)13-29 cm, erect, usually narrowly pyramidal, open, sparse, with 30-100 spikelets, proximal internodes usually 4+ cm, with (1)2-4(5) branches per node; branches 2.5-18 cm, spreading to eventually reflexed, fairly flexuous, terete to weakly angled, sparsely to moderately scabrous, with 3-34 spikelets. |
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Spikelets | 3-5.6 mm, laterally compressed; florets 2-5; rachilla internodes glabrous, usually shorter than 1 mm. |
3-8 mm, lengths 3.5 times widths, laterally compressed, not sexually dimorphic; florets 2-8; rachilla internodes 1+ mm, smooth, glabrous. |
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Glumes | 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. |
narrowly lanceolate, distinctly keeled; lower glumes 1.6-3.5 mm, 1(3)-veined, 1/2-1/3 as long as the adjacent lemmas; upper glumes 2.2-4.9 mm; calluses webbed, hairs over 1/2 the lemma length; lemmas 2.6-5 mm, lanceolate, distinctly keeled, keels and marginal veins long-villous, extending 1/2 - 2/3 the keel length, 1/3-1/2 the marginal vein length, lateral veins sometimes short-villous, the lateral veins obscure to moderately prominent, intercostal regions usually sparsely softly puberulent, margins glabrous, apices acute; palea keels scabrous, rarely softly puberulent at midlength; anthers vestigial (0.1-0.2 mm) or (1.3)2-3 mm. |
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2n | = 28, 28+1. |
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Poa saltuensis |
Poa tracyi |
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Distribution |
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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CO; NM |
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Discussion | 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.) |
Poa tracyi grows primarily in coniferous forest openings, sometimes with gambel oak, and in subalpine mesic meadows. It is restricted to the front ranges of the southern Rocky Mountains; it is not common. It differs from P. occidentalis (p. 536) in having longer and/or rudimentary anthers, shorter ligules relative to the leaf blade width, and a loose, shortly rhizomatous habit. Retrorsely pubescent sheaths are common in the more southern plants. It is sequentially gynomonoecious. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 24, p. 510. | FNA vol. 24, p. 543. | ||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Sylvestres | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Poa | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | P. saltuensis var. microlepis, P. languida | |||||
Name authority | Fernald & Wiegand | Vasey | ||||
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