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Letterman bluegrass, Letterman's blue grass

Alaska blue grass, few-flower bluegrass

Habit Plants perennial; not glaucous; densely tufted, not stoloniferous, not rhizomatous. Plants perennial; slightly or loosely tufted, not stoloniferous, not rhizomatous.
Culms

1-12 cm, slender.

10-30 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 1/4 - 3/5 their length, terete;

ligules 1-2 mm, smooth or sparsely scabrous, truncate to obtuse;

blades 1-3 mm wide, flat, thin, soft, apices broadly prow-shaped.

Basal branching

all or mainly intra-vaginal.

mainly extravaginal.

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.

2.5-10 cm, lax to nearly erect, open, sparse, with 1-2 branches per node;

branches (2)3-6 cm, ascending to spreading, lower branches infrequently reflexed, lax or drooping, capillary, terete to slightly sulcate, usually smooth, rarely some branches within a panicle sparsely scabrous, with 1-3(5) spikelets.

Spikelets

3-4 mm, laterally compressed, green or anthocyanic;

florets 2-3;

rachilla internodes shorter than 1 mm, smooth.

4-6 mm, laterally compressed, broadly lanceolate to ovate, usually dark purple, with 3-5 florets;

rachilla internodes 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.

lanceolate to broadly lanceolate, thin, distinctly keeled, keels smooth or nearly so;

lower glumes 1-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses sparsely webbed;

lemmas 3-4 mm, broadly lanceolate, usually strongly purple, distinctly keeled, thin, keels and marginal veins short- to long-villous, keels hairy for 1/2-1/3 their length, lateral veins glabrous, intercostal regions smooth, glabrous, margins glabrous, not infolded, apices acute, sometimes slightly bronze-colored;

palea keels sparsely scabrous at midlength;

anthers 0.4-1 mm.

2n

= 14.

= 28, 42.

Poa lettermanii

Poa paucispicula

Distribution
from FNA
CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; MT; WA; AB; BC; NT; YT
[WildflowerSearch map]
[BONAP county map]
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 paucispicula grows in arctic and alpine regions, from the north coast of Alaska and the western Northwest Territories south to Washington, Idaho, and Wyoming; it also grows in arctic far east Russia. It is a delicate species that prefers open, mesic, rocky slopes. It has sometimes been included in P. leptocoma (p. 573), a member of Poa sect. Oreinos. It differs from P. leptocoma in having smoother branches, fewer spikelets, and broader glumes. Chloroplast DNA studies confirm that it is not closely related to species of sect. Oreinos; ITS data support its relationship to P. leptocoma.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 24, p. 580. FNA vol. 24, p. 538.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Abbreviatae Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Homalopoa
Sibling taxa
P. abbreviata, P. alpina, P. alsodes, P. ammophila, P. annua, P. arachnifera, P. arctica, P. arida, P. arnowiae, P. atropurpurea, P. autumnalis, P. bigelovii, P. bolanderi, P. bulbosa, P. chaixii, P. chambersii, P. chapmaniana, P. compressa, P. confinis, P. curtifolia, P. cusickii, P. cuspidata, P. diaboli, P. douglasii, P. eminens, P. fendleriana, P. glauca, P. hartzii, P. howellii, P. infirma, P. interior, P. keckii, P. kelloggii, P. laxa, P. laxa × glauca, P. laxiflora, P. leibergii, P. leptocoma, P. macrantha, P. macrocalyx, P. marcida, P. napensis, P. nemoralis, P. nervosa, P. occidentalis, P. paludigena, P. palustris, P. paucispicula, P. piperi, P. porsildii, P. pratensis, P. pringlei, P. pseudoabbreviata, P. reflexa, P. rhizomata, P. saltuensis, P. secunda, P. sierrae, P. stebbinsii, P. stenantha, P. strictiramea, P. sublanata, P. suksdorfii, P. supina, P. sylvestris, P. tenerrima, P. tracyi, P. trivialis, P. unilateralis, P. wheeleri, P. wolfii, P. ×gaspensis, P. ×limosa, P. ×nematophylla
P. abbreviata, P. alpina, P. alsodes, P. ammophila, P. annua, P. arachnifera, P. arctica, P. arida, P. arnowiae, P. atropurpurea, P. autumnalis, P. bigelovii, P. bolanderi, P. bulbosa, P. chaixii, P. chambersii, P. chapmaniana, P. compressa, P. confinis, P. curtifolia, P. cusickii, P. cuspidata, P. diaboli, P. douglasii, P. eminens, P. fendleriana, P. glauca, P. hartzii, P. howellii, P. infirma, P. interior, P. keckii, P. kelloggii, P. laxa, P. laxa × glauca, P. laxiflora, P. leibergii, P. leptocoma, P. lettermanii, P. macrantha, P. macrocalyx, P. marcida, P. napensis, P. nemoralis, P. nervosa, P. occidentalis, P. paludigena, P. palustris, P. piperi, P. porsildii, P. pratensis, P. pringlei, P. pseudoabbreviata, P. reflexa, P. rhizomata, P. saltuensis, P. secunda, P. sierrae, P. stebbinsii, P. stenantha, P. strictiramea, P. sublanata, P. suksdorfii, P. supina, P. sylvestris, P. tenerrima, P. tracyi, P. trivialis, P. unilateralis, P. wheeleri, P. wolfii, P. ×gaspensis, P. ×limosa, P. ×nematophylla
Synonyms P. mor.tevansi P. leptocoma var. paucispicula, P. leptocoma subsp. paucispicula
Name authority Vasey Scribn. & Merr.
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