Poa arctica subsp. lanata

(Scribn. & Merr.) Soreng
Synonyms: Poa malacantha Poa lanata
Treatment appears in FNA Volume 24. Treatment on page 532.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Plants usually densely, infrequently loosely, tufted, rhizomes short, fairly stout, sometimes poorly developed. Basal branching frequently intravaginal. Sheaths persistent; ligules 2-4 mm, obtuse to acute; blades 2-6 mm wide, usually flat, firm and fairly persistent, flag leaf-blades (1.5) 2.5-9 cm. Panicles lax to erect, open; branches ascending or widely spreading, somewhat sinuous and flexuous to fairly stout and straight, smooth to sparsely or moderately scabrous, with (1) 2-3 (5) spikelets, proximal branches 2/5-3/5 the panicle length. Spikelets (5) 6-8 mm, infrequently bulbiferous; rachilla internodes sometimes muriculate, sparsely to moderately long-villous or glabrous. Glumes keeled, keels compressed, smooth or moderately scabrous; calluses webbed in normal plants, web copious, sometimes glabrous in bulbiferous plants; lemmas 4.5-6 (7) mm; palea keels short to long-villous, sometimes scabrous in bulbiferous plants; anthers usually fully developed in sexual plants, poorly developed in bulbiferous plants. 2n = 42, 56, 62, 70, 75, 78, 80.

Discussion

Poa arctica subsp. lanata is amphiberingian in distribution, extending to northwestern British Columbia. It often grows with subsp. arctica, from which it differs in having larger and, usually, fewer spikelets and broader leaves. It intergrades with P. macrocalyx (p. 527) in one direction and P. arctica subsp. arctica in another.

Poa malacantba Kom. is included here in P. arctica subsp. lanata. It supposedly differs in having soft hairs on the rachilla internodes and smaller spikelets, but neither feature excludes it from subsp. lanata. Bulbiferous forms of Poa arctica subsp. lanata are known primarily from uplands in the Alaska Range and Kenai Peninsula. The type of P. lanata var. vivipara Hulten is a robust plant that appears to belong to P. macrocalyx consequently the name cannot be applied to bulbiferous plants of subsp. lanata.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Poa arctica subsp. lanata"
80 +, 78 +, 75 +, 70 +, 62 +, 56 +  and 42 +
membranous +  and scarious +
hairy +, scabrous +  and smooth +
5 cm50 mm <br />0.05 m <br /> (?) +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
scarious-hyaline +
Robert J. Soreng +
(Scribn. & Merr.) Soreng +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
keeled +  and rounded +
strigose +  and glabrous +
not branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
persistent +
not evident +
folded +  and flat +
2mm;6mm +
straight +, flexuous +  and sinuous +
spreading;ascending +
hispidulous +, glabrous +, smooth or +  and sparsely densely scabrous +
glabrous +  and webbed +
compressed +  and terete +
reduced +  and subequal +
unbranched +  and hollow +
ascending +  and erect +
compressed +  and terete +
slender +  and stout +
7.5 cm75 mm <br />0.075 m <br /> (60 cm600 mm <br />0.6 m <br />) +
not woody +
Mont. +, Wyo. +, Colo. +, N.Mex. +, Wash. +, Utah +, Alaska +, Alta. +, B.C. +, Greenland +, Man. +, Nfld. and Labr. +, N.W.T. +, Nunavut +, Ont. +, Que. +, Sask. +, Yukon +, Idaho +  and Nev. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
3 +  and 6 +
compressed +
reduced +
1-3(5)-veined +
shorter or longer +
subtending +
subequal +  and unequal +
distributed +
uncinate +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
0 +  and 1/6 +
Oval (?) +  and Round (?) +
milky white +  and slightly greenish +
glabrous +, puberulent +, short-villous +  and softly puberulent +
prominent +  and pronounced +
5(7-11)-veined +
hairy +, glabrous +  and chartaceous +
keeled +, lanceolate +  and broadly lanceolate +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
membranous +
erose +  and entire +
white +  and milky white or hyaline +
obtuse +  and acute +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
membranous +
inconspicuous +
lobed +  and lanceolate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
concealed +  and prominent +
0 +  and 5 +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
2 cm20 mm <br />0.02 m <br /> (?) +
ovoid +  and broadly pyramidal +
3.5 cm35 mm <br />0.035 m <br /> (15 cm150 mm <br />0.15 m <br />) +
dry +  and fleshy +
1.5 cm15 mm <br />0.015 m <br /> (?) +
glabrous +  and long-villous +
persistent +
compressed +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Poa malacantha +  and Poa lanata +
Poa arctica subsp. lanata +
Poa arctica +
subspecies +
membranous +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
parallel +  and converging +
aquatic +  and terrestrial +