Poa pratensis subsp. irrigata

(Lindm.) H. Lindb.
Synonyms: Poa subcaerulea
Treatment appears in FNA Volume 24. Treatment on page 526.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Plants moderately densely to loosely tufted, sometimes forming turf, culms solitary. Basal branching mainly extravaginal. Culms 8-30 (50) cm. Innovation shoot blades usually shorter than 15 cm, 2-4.5 mm wide, adaxial surfaces usually glabrous; cauline blades flat. Panicles 2-10 cm, broadly pyramidal, open, with 1-2 (5) branches per node; branches 1.5-6 cm, widely spreading, smooth or sparsely to moderately scabrous, with 4-8 spikelets. Spikelets lanceolate to broadly lanceolate, not bulbiferous; florets normal. Glume keels distinct, sparsely to moderately scabrous; lower and upper glumes often nearly equaling the lowest lemmas, often noticeably glaucous; lemmas 3-5 (6) mm, finely muriculate, lateral-veins glabrous; palea keels scabrous, glabrous, intercostal regions glabrous. 2n = 54, 56, 65, 80, 82-147.

Discussion

Poa pratensis subsp. irrigata is poorly understood in the Flora region. As interpreted here, it includes subarctic to boreal, coastal and lowland plants that differ from those of subsp. pratensis in their primarily extravaginal branching, shorter stature, wide, flat blades, short, stout panicles with fewer branches, larger spikelets, and relatively longer glumes that are often pruinose.

Selected References

None.

Lower Taxa

None.

"thin" is not a number."decumbent" is not a number.

membranous +  and scarious +
5 cm50 mm <br />0.05 m <br /> (?) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
scarious-hyaline +
acute +  and prow--shaped +
Robert J. Soreng +
(Lindm.) H. Lindb. +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
keeled +  and rounded +
strigose +  and glabrous +
not branching +
intravaginal +, extravaginal +, branching +  and basal +
not swollen +, compressed +  and terete +
swelling +
not evident +
involute +, folded +  and flat +
subequal +
1 cm10 mm <br />0.01 m <br /> (?) +
flexuous +  and straight +
hispidulous +, glabrous +, smooth or +  and sparsely densely scabrous +
angled +  and terete +
1.5 cm15 mm <br />0.015 m <br /> (6 cm60 mm <br />0.06 m <br />) +
compressed +  and terete +
involute +, folded +  and flat +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
extravaginal +  and basal +
compressed +  and terete +
8 cm80 mm <br />0.08 m <br /> (30 cm300 mm <br />0.3 m <br />) +
not woody +
Conn. +, N.J. +, N.Y. +, Wash. +, Va. +, Del. +, D.C. +, Wis. +, W.Va. +, Pacific Islands (Hawaii) +, Mass. +, Maine +, N.H. +, R.I. +, Vt. +, Fla. +, Wyo. +, N.Mex. +, Tex. +, La. +, Puerto Rico +, Tenn. +, N.C. +, S.C. +, Pa. +, Calif. +, Nev. +, Colo. +, Alaska +, Ill. +, Md. +, Minn. +, Mont. +, Ala. +, Ark. +, Ariz. +, Ga. +, Iowa +, Idaho +, Ind. +, Kans. +, Ky. +, Mich. +, Mo. +, Miss. +, N.Dak. +, Nebr. +, Ohio +, Okla. +, Oreg. +, S.Dak. +, Utah +, Alta. +, B.C. +, Greenland +, Man. +, N.B. +, Nfld. and Labr. +, N.S. +, N.W.T. +, Nunavut +, Ont. +, P.E.I. +, Que. +, Sask. +  and Yukon +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
2 +  and 5 +
compressed +
reduced +
1-3(5)-veined +
usually distinctly shorter +
shorter or longer +
subtending +
keeled +, lanceolate +  and narrowly lanceolate +
unequal +  and subequal +
distributed +
straight +, sinuous +  and curving +
erect +  and appressed +
uncinate +
slender +
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 (?) +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
milky white +  and slightly greenish +
puberulent +  and long-villous +
5(7-11)-veined +
purple-tinged +  and green +
hairy +, glabrous +  and chartaceous +
muriculate +
keeled +  and lanceolate +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
membranous +
erose +  and entire +
white +  and milky white or hyaline +
glabrous +  and ciliolate +
obtuse +, truncate +  and rounded +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
membranous +
inconspicuous +
lobed +  and lanceolate +
sickle--shaped +, usually narrowly lanceolate +  and lanceolate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
muriculate +  and smooth +
1 +  and 2 +
compressed +  and terete +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
20 cm200 mm <br />0.2 m <br /> (?) +
pyramidal +
2 cm20 mm <br />0.02 m <br /> (10 cm100 mm <br />0.1 m <br />) +
dry +  and fleshy +
hairy +, infrequently sparsely +  and glabrous +
terete +  and slightly compressed +
not bulbiferous +
lanceolate +  and broadly lanceolate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Poa subcaerulea +
Poa pratensis subsp. irrigata +
Poa pratensis +
subspecies +
membranous +
0.2 cm2 mm <br />0.002 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
parallel +  and converging +
anthocyanic +  and green +
aquatic +  and terrestrial +