Poa pratensis subsp. alpigena

(Lindm.) Hiitonen
Common names: Alpigene bluegrass
Synonyms: Poa alpigena Poa rigens Hartm.
Treatment appears in FNA Volume 24. Treatment on page 525.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Plants strongly anthocyanic; moderately to loosely tufted, shoots usually solitary. Basal branching mainly extravaginal. Culms 15-70 cm. Innovation shoot blades shorter than 15 cm, 1-3.6 mm wide, flat or folded, soft, adaxial surfaces usually glabrous, sometimes sparsely pubescent; cauline blades flat or folded. Panicles 3-13 (20) cm, narrowly pyramidal or contracted, expanding well after emergence from the sheath, with (1) 2-5 (7) branches per node; branches 1-6 cm, steeply ascending to eventually spreading or somewhat reflexed, smooth or sparsely scabrous, with 5-15 spikelets. Spikelets 4-5.5 mm, narrowly lanceolate, not bulbiferous; florets normal. Glume keels distinct, smooth or sparsely scabrous near the apices; upper glumes nearly equaling the lowest lemmas; lemmas 2.5-3.5 mm, smooth or finely muriculate, lateral-veins frequently short-villous to softly puberulent; palea keels scabrous, often softly puberulent at midlength, intercostal regions usually glabrous, rarely sparsely hispidulous. 2n = 28, 32, 35, 42, 48, 50, 53, 56, 60, 63, 64, 65, 61, ca. 68, 69, 70, 72, 73, 74, 76, 77, 78, 79, 82, 84, 86, 88, 89, 92, 94.

Discussion

Poa pratensis subsp. alpigena is a circumpolar, mesophytic to subhydrophytic, arctic and alpine subspecies that extends into boreal forests in northern parts of the Flora region. It is infrequent south of Canada, with isolated collections being known from as far south as New Mexico in the Rocky Mountains, and New Hampshire and Maine in the east. It also grows in southern Patagonia.

Poa pratensis subsp. alpigena approaches P. arctica (p. 529). It differs in being glabrous between the lemma and palea veins, having somewhat more dense, later-opening panicles, and, usually, having smaller spikelets and more closely spaced palea keels. It differs from a likely hybrid with P. alpina, P. xgaspensis (p. 601), in its truncate to rounded ligules, lemmas that are glabrous between the veins, and the lack of a basal tuft of leaves. In this treatment, bulbiferous plants are placed in subsp. colpodea, a subspecies which is more common than subsp. alpigena in the high arctic. The two sometimes grow together; there is some evidence of a shift in dominance from year to year.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

94 +, 92 +, 89 +, 88 +, 86 +, 84 +, 82 +, 79 +, 78 +, 77 +, 76 +, 74 +, 73 +, 72 +, 70 +, 69 +, 68 +, 61 +, 65 +, 64 +, 63 +, 60 +, 56 +, 53 +, 50 +, 48 +, 42 +, 35 +, 32 +  and 28 +
membranous +  and scarious +
pubescent +  and glabrous +
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 +
Robert J. Soreng +
(Lindm.) Hiitonen +
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 +
thin;thick +
1 cm10 mm <br />0.01 m <br /> (?) +
flexuous +  and straight +
reflexed;steeply ascending;eventually spreading +
hispidulous +, glabrous +, smooth or +  and sparsely densely scabrous +
angled +  and terete +
compressed +  and terete +
folded +  and flat +
Alpigene bluegrass +
unbranched +  and hollow +
compressed +  and terete +
15 cm150 mm <br />0.15 m <br /> (70 cm700 mm <br />0.7 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 +
frequently short-villous +  and softly puberulent +
5(7-11)-veined +
purple-tinged +  and green +
hairy +, glabrous +  and chartaceous +
muriculate +  and smooth +
keeled +  and lanceolate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 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 +
expanding +
3 cm30 mm <br />0.03 m <br /> (13 cm130 mm <br />0.13 m <br />) +
dry +  and fleshy +
hairy +, infrequently sparsely +  and glabrous +
terete +  and slightly compressed +
not bulbiferous +
5 +  and 15 +
lanceolate +
0.4 cm4 mm <br />0.004 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Poa alpigena +  and Poa rigens +
Poa pratensis subsp. alpigena +
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 +
aquatic +  and terrestrial +