Poa cusickii subsp. epilis

(Scribn.) W.A. Weber
Common names: Skyline bluegrass
Endemic
Synonyms: Poa epilis
Treatment appears in FNA Volume 24. Treatment on page 560.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Plants densely tufted. Basal branching intra and extravaginal. Culms 20-45 cm, mostly erect, with 1-2 well-exserted nodes. Sheaths closed for 1/3-3/4 their length, distal sheath lengths 2-5 times blade lengths; innovation blades 0.7-1 mm wide; cauline blades more than 1.5 mm wide, flat or folded, apices narrowly to broadly prow-shaped, flag leaf-blades 1.5-5 cm, apices broadly prow-shaped. Panicles usually 2-7 cm, usually contracted, with 20-70 spikelets; nodes with 2-5 branches; branches 1-3 cm, moderately stout, smooth to sparsely scabrous, with 1-8 spikelets. Spikelets (3) 4-8 mm. Calluses glabrous; lemmas 3-6 mm, glabrous or, rarely, the keels and marginal veins sparsely puberulent proximally; anthers usually aborted late in development. 2n = 56, ca. 70.

Discussion

Poa cusickii subsp. epilis tends to grow around timberline. It is strictly pistillate. It is usually quite distinct from subspp. cusickii and pallida, and differs from subsp. purpurascens in having on average more and shorter spikelets, lemmas that are shorter and rarely pubescent, and both intra- and extravaginal branching. It occurs throughout most of the range of the species, but is absent from the Yukon Territory, and uncommon in the Cascade Mountains. It is fairly uniform even though widespread.

Selected References

None.

Lower Taxa

None.

"reduced" is not a number.No values specified."decumbent" is not a number.

membranous +  and scarious +
glabrous +, hispidulous +  and softly puberulent +
5 cm50 mm <br />0.05 m <br /> (?) +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
scarious-hyaline +
prow--shaped +
Robert J. Soreng +
(Scribn.) W.A. Weber +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
keeled +  and rounded +
strigose +  and glabrous +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
compressed +  and terete +
swelling +
not evident +
involute +, folded +  and flat +
5 cm50 mm <br />0.05 m <br /> (?) +
ascending;erect +
hispidulous +, glabrous +, scabrous +  and smooth +
scabrous +  and smooth to sparsely +
terete +  and angled +
slender +  and stout +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
compressed +  and terete +
folded +  and flat +
soft +  and firm +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
glabrous +, scabrous +  and smooth +
Skyline bluegrass +
unbranched +  and hollow +
10 cm100 mm <br />0.1 m <br /> (60 cm600 mm <br />0.6 m <br />) +
compressed +  and terete +
20 cm200 mm <br />0.2 m <br /> (45 cm450 mm <br />0.45 m <br />) +
not woody +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
Nev. +, Colo. +, Wash. +, Wyo. +, Utah +, Calif. +, Oreg. +, Mont. +, Alta. +, B.C. +, Man. +, Sask. +, Yukon +, Idaho +  and N.Dak. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
2 +  and 6 +
compressed +
reduced +
2mm +  and 10mm +
1-3(5)-veined +
shorter or longer +
subtending +
keeled +  and lanceolate +
unequal +
distributed +
0 +  and 1/4 +
uncinate +
0.1 cm1 mm <br />0.001 m <br /> (?) +
0 +  and 1/6 +
Oval (?) +  and Round (?) +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
milky white +  and slightly greenish +
puberulent +
obscure +  and prominent +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
5(7-11)-veined +
, +  and glabrous +
keeled +, lanceolate +  and broadly lanceolate +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
membranous +  and thinly membranous +
erose +  and entire +
colorless +  and milky white +
ciliolate +  and glabrous +
truncate +  and acuminate +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
membranous +
inconspicuous +
lobed +  and lanceolate +
milky white +  and slightly greenish +
concealed +  and prominent +
0 +  and 2 +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
12 cm120 mm <br />0.12 m <br /> (?) +
narrowly lanceoloid +  and ovoid +
2 cm20 mm <br />0.02 m <br /> (7 cm70 mm <br />0.07 m <br />) +
dry +  and fleshy +
hairy +, glabrous +, scabrous +  and smooth +
glabrous +, scabrous +  and smooth +
rhizomatous +  and stoloniferous +
not bulbiferous +
compressed +, broadly lanceolate +  and narrowly ovate +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Poa epilis +
Poa cusickii subsp. epilis +
Poa cusickii +
subspecies +
membranous +
5-veined +  and 3-veined +
parallel +  and converging +
aquatic +  and terrestrial +