Poa cusickii subsp. purpurascens

(Vasey) Soreng
Endemic
Treatment appears in FNA Volume 24. Treatment on page 562.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Plants densely to moderately densely tufted. Basal branching mostly extravaginal. Culms 25-50 cm, bases decumbent, with 1-2 well-exserted nodes. Sheaths closed for 1/2-3/4 their length, distal sheath lengths 1.6-5 times blade lengths; innovation blades mostly 1-2 mm wide; cauline blades more than 1.5 mm wide, flat or folded, apices usually broadly prow-shaped, flag leaf-blades 3-6 cm. Panicles usually 4-7 cm, slightly lax, ovate, loosely contracted, with 13-50 spikelets; nodes with 1-3 branches; branches 1-3 (4) cm, moderately stout, smooth to moderately scabrous, with 1-8 spikelets. Spikelets 7-10 mm. Calluses of proximal lemmas usually sparsely and shortly webbed, hairs less than 1/4 the lemma length, sometimes glabrous, those of the distal lemmas glabrous; lemmas 4-7 mm, usually the keels and marginal veins of some proximal lemmas sparsely puberulent near the base, sometimes glabrous, distal lemmas glabrous; anthers usually aborted late in development. 2n = 28+11, 56.

Discussion

Poa cusickii subsp. purpurascens grows in subalpine habitats in the coastal mountains from southern British Columbia to southern Oregon, with sporadic occurrences eastward in British Columbia to the Rocky Mountains and south to the central Sierra Nevada. It tends to differ from subsp. epilis in having predominantly extravaginal branching, fewer and longer spikelets, and longer lemmas that are usually sparsely hairy on the keel and marginal veins. It differs from P. chambersii (p. 548) in lacking rhizomes and in being strictly pistillate; and from P. porsildii (p. 563) in its longer spikelets and in tending to have longer panicles with more spikelets.

Selected References

None.

Lower Taxa

None.

"reduced" is not a number.No values specified."decumbent" is not a number."glabrous" 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 +
(Vasey) Soreng +
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 +
4 cm40 mm <br />0.04 m <br /> (?) +
ascending;erect +
hispidulous +, glabrous +, scabrous +  and smooth +
scabrous +  and smooth to moderately +
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 +
unbranched +  and hollow +
10 cm100 mm <br />0.1 m <br /> (60 cm600 mm <br />0.6 m <br />) +
compressed +  and terete +
25 cm250 mm <br />0.25 m <br /> (50 cm500 mm <br />0.5 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 (?) +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
milky white +  and slightly greenish +
glabrous +  and 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 +
keeled +, lanceolate +  and broadly lanceolate +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 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 +
glabrous +  and puberulent +
concealed +  and prominent +
0 +  and 2 +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
12 cm120 mm <br />0.12 m <br /> (?) +
4 cm40 mm <br />0.04 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 +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Poa cusickii subsp. purpurascens +
Poa cusickii +
subspecies +
membranous +
5-veined +  and 3-veined +
parallel +  and converging +
aquatic +  and terrestrial +