Poa lettermanii |
Poa marcida |
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Letterman bluegrass, Letterman's blue grass |
weeping bluegrass, withered blue grass |
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Habit | Plants perennial; not glaucous; densely tufted, not stoloniferous, not rhizomatous. | Plants perennial; not rhizomatous, not stoloniferous, sometimes shortly rhizomatous, loosely to densely tufted. |
Culms | 1-12 cm, slender. |
20-80 cm. |
Sheaths | closed for 1/6 – 1/4 their length, terete; ligules 1-3 mm, milky white to hyaline, smooth; blades 0.5-2 mm wide, flat or folded, or slightly inrolled, thin, without papillae (at 100x), apices narrowly prow-shaped. |
closed for at least 9/10 their length; ligules 0.5-2 mm, smooth, truncate; blades 1.5-5 mm wide, flat, lax. |
Basal branching | all or mainly intra-vaginal. |
mainly pseudointravaginal. |
Panicles | 1-3 cm, erect, contracted, usually exserted from the sheaths; branches to 1.5 cm, erect to steeply ascending, slender, sulcate or angled, smooth or the angles sparsely scabrous; pedicels shorter than the spikelets. |
6-22 cm, lax, narrowly lanceoloid, sparse; nodes with 1-3 branches; branches ascending, lax, angled, angles scabrous. |
Spikelets | 3-4 mm, laterally compressed, green or anthocyanic; florets 2-3; rachilla internodes shorter than 1 mm, smooth. |
3.5-7 mm laterally compressed; florets (1)2(4); rachilla internodes about 1 mm, smooth, glabrous. |
Glumes | usually equaling or exceeding the lowest lemmas, sometimes also equaling or exceeding the upper florets, lanceolate to broadly lanceolate, distinctly keeled, keels smooth; lower glumes 3-veined; calluses glabrous; lemmas 2.5-3 mm, lanceolate, distinctly keeled, thin, usually glabrous, keels and marginal veins rarely sparsely puberulent proximally, apices acute; palea keels scabrous; anthers 0.2-0.8 mm. |
distinctly keeled, keels scabrous; lower glumes 1-veined; upper glumes shorter than or subequal to the lowest lemmas; calluses webbed, webs sparse; lemmas 3.2-5 mm, narrowly lanceolate, distinctly keeled, glabrous, acuminate; palea keels scabrous, sometimes sparsely so; anthers 0.5-1.2 mm. |
2n | = 14. |
= unknown. |
Poa lettermanii |
Poa marcida |
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Distribution |
CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC
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OR; WA; BC |
Discussion | Poa lettermanii grows on rocky slopes of the highest peaks and ridges in the alpine zone, from northern British Columbia to western Alberta and south to California and Colorado, usually in the shelter of rocks or on mesic to wet, frost-scarred slopes. It is one of only three known diploid Poa species native to the Western Hemisphere. Its glabrous calluses and lemmas usually distinguish it from P. abbreviata (p. 582); it also differs in having flat or folded leaf blades, and shorter spikelets with glumes that are longer than the adjacent florets. Poa montevansii E.H. Kelso is tentatively included here, although its slightly longer lemmas that slightly exceed the glumes suggest that it may represent rare, glabrous forms of P. abbreviata. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Poa marcida is an uncommon endemic of breaks in rich, mesic, generally old growth forests of the Pacific coast, from Vancouver Island through the western foothills of the northern Cascade Mountains to central Oregon. It differs from P. saltuensis (p. 510) in its closed sheaths and attenuate lemmas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 580. | FNA vol. 24, p. 512. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Abbreviatae | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Sylvestres |
Sibling taxa | ||
Synonyms | P. mor.tevansi | |
Name authority | Vasey | Hitchc. |
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