The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Letterman bluegrass, Letterman's blue grass

old-pasture blue grass

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

1-12 cm, slender.

20-95 cm tall, 0.8-1.5 mm thick.

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 1/3-2/3 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.

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.

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.

Spikelets

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

florets 2-3;

rachilla internodes shorter than 1 mm, smooth.

3-5.6 mm, laterally compressed;

florets 2-5;

rachilla internodes glabrous, usually shorter than 1 mm.

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.

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.

2n

= 14.

Poa lettermanii

Poa saltuensis

Distribution
from FNA
CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
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
[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 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.)

Key
1. Anthers 0.4-1 mm long; lemma apices obtuse to acute, firm or scarious for up to 0.25 mm
subsp. languida
1. Anthers 0.9-1.5 mm long; lemma apices acute to acuminate, scarious for 0.25-0.5 mm
subsp. saltuensis
Source FNA vol. 24, p. 580. FNA vol. 24, p. 510.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Abbreviatae Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Sylvestres
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. paucispicula, P. piperi, P. porsildii, P. pratensis, P. pringlei, P. pseudoabbreviata, P. reflexa, P. rhizomata, 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
Subordinate taxa
P. saltuensis subsp. languida, P. saltuensis subsp. saltuensis
Synonyms P. mor.tevansi P. saltuensis var. microlepis, P. languida
Name authority Vasey Fernald & Wiegand
Web links