Poa pratensis subsp. pratensis

Synonyms: Poa peckii
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 densely to loosely tufted, often forming turf, culms clustered. Basal branching intra and extravaginal. Culms 8-100 cm. Innovation shoot blades 10-45 cm long, 0.4-4 mm wide, some distinctly narrower than the cauline blades, all flat or some involute, usually soft, adaxial surfaces sparsely pubescent; cauline blades flat or folded. Panicles 5-18 cm, broadly pyramidal, open or somewhat contracted, with 3-5 (7) branches per node; branches spreading to somewhat reflexed, smooth or sparsely to fairly densely scabrous, with several to many spikelets per branch. Spikelets lanceolate to broadly lanceolate, not bulbiferous; florets normal. Glume keels strongly compressed, sparsely to moderately scabrous; upper glumes shorter than or nearly equaling the lowest lemmas; lemmas 2.8-4.3 mm, finely muriculate, lateral-veins glabrous; palea keels scabrous, glabrous, intercostal regions glabrous. 2n = 43, 44, 48,49, 50, 51, 52, 54,56, 58, 59, 62, 65, 66, 61, 74, ca. 85, ca. 86, 88, 89, 95.

Discussion

Poa pratensis subsp. pratensis grows throughout most cf the range of the species, but is absent from the high arctic, and only sporadic in the low arctic. It usually has a few narrow, flat or involute, intravaginal shoot leaves, in addition to some broader, extravaginal shoot leaves, and is intermediate between subspp. angustifolia and irrigata. For a comparison, see the descriptions of those subspecies.

Selected References

None.

Lower Taxa

None.

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

95 +, 89 +, 88 +, 86 +, 85 +, 74 +, 61 +, 66 +, 65 +, 62 +, 59 +, 58 +, 56 +, 54 +, 52 +, 51 +, 50 +, 49 +, 48 +, 44 +  and 43 +
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 +
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 +
reflexed;spreading to somewhat +
hispidulous +, glabrous +, smooth or +  and sparsely densely scabrous +
angled +  and terete +
2 cm20 mm <br />0.02 m <br /> (9 cm90 mm <br />0.09 m <br />) +
compressed +  and terete +
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 /> (100 cm1,000 mm <br />1 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 +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.43 cm4.3 mm <br />0.0043 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 +
5 cm50 mm <br />0.05 m <br /> (18 cm180 mm <br />0.18 m <br />) +
dry +  and fleshy +
hairy +, infrequently sparsely +  and glabrous +
terete +  and slightly compressed +
not bulbiferous +
several +  and many +
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 peckii +
Poa pratensis subsp. pratensis +
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 +