Bromus pumpellianus

Scribn.
Common names: Arctic brome
Synonyms: Bromus pumpellianus var. arcticus Bromus inermis subsp. pumpellianus Bromus inermis var. purpurascens Bromopsis pumpelliana var. arctica Bromopsis pumpelliana Bromopsis inermis subsp. pumpellianus
Treatment appears in FNA Volume 24. Treatment on page 207.

Plants perennial; usually rhizomatous, sometimes cespitose, rhizomes short to long-creeping. Culms 50-135 cm, erect or ascending, sometimes geniculate, usually single or few together, sometimes clumped; nodes 2-7, pubescent or glabrous; internodes glabrous or pubescent. Sheaths pilose, villous, or glabrous; auricles sometimes present on the lower leaves; ligules to 4 mm, glabrous, truncate or obtuse, erose; blades 7-30 cm long, 2.5-8.5 (9) mm wide, flat, pubescent or glabrous on both surfaces, sometimes only the adaxial surface pubescent. Panicles 10-24 cm, open or contracted, erect or nodding; branches erect to spreading. Spikelets 16-32 (45) mm, elliptic to lanceolate, terete to moderately laterally compressed, sometimes purplish, with 4-14 florets. Glumes glabrous or hairy; lower glumes (4) 5-10 mm, 1 (3) -veined; upper glumes (5) 7.5-13 mm, 3-veined; lemmas 9-16 mm, lanceolate, rounded over the midvein, sparsely to densely hairy throughout, or on the margins and lower portion of the back, or along the marginal veins and keel, apices subulate to acute, entire or slightly emarginate, lobes shorter than 1 mm; awns usually present, sometimes absent, to 7.5 mm, straight, arising less than 1.5 mm below the lemma apices; anthers 3.5-7 mm. 2n = 28, 56.

Discussion

The range of Bromus pumpellianus extends from Asia to North America, where it includes Alaska, the western half of Canada, the western United States as far south as New Mexico, and a few other locations eastward. It is sometimes treated as a subspecies of B. inermis. It differs from that species primarily in its tendency to have pubescent lemmas, nodes, and leaf blades.

Two subspecies that differ in morphology and distribution are described below. Both strongly resemble the recently introduced Bromus riparius, differing in the case of B. pumpellianus subsp. pumpellianus in having longer rhizomes, or, in the case of B. pumpellianus subsp. dicksonii, in having a more restricted distribution. It is possible that the description and distribution of B. pumpellianus may be based in part on misidentification of B. riparius, as many taxonomists may have been unaware of the introduction of the latter species to North America.

Selected References

None.

Key

1 Panicles usually open; plants cespitose, sometimes shortly rhizomatous; culms ascending, often geniculate; nodes glabrous or pubescent; plants of the Yukon River drainage Bromus pumpellianus subsp. dicksonii
1 Panicles contracted to open; plants rhizomatous; culms erect; nodes usually pubescent; plants of the range of the species Bromus pumpellianus subsp. pumpellianus

"decumbent" is not a number.

... more about "Bromus pumpellianus"
membranous +  and scarious +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
emarginate +  and entire +
subulate +  and acute +
Leon E. Pavlickf +
Scribn. +
1 (?) +  and 3 (?) +
straight +
distinct +
subterminal +  and terminal +
geniculate +
0 cm0 mm <br />0 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
7 cm70 mm <br />0.07 m <br /> (30 cm300 mm <br />0.3 m <br />) +
not evident +
glabrous +  and pubescent +
cross +, linear +  and narrowly lanceolate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.85 cm8.5 mm <br />0.0085 m <br />) +
erect;spreading +
spikelike +
Arctic brome +
not branching +
ascending +  and erect +
geniculate +
50 cm500 mm <br />0.5 m <br /> (135 cm1,350 mm <br />1.35 m <br />) +
not woody +
Conn. +, Mass. +, N.H. +, N.J. +, N.Y. +, Calif. +, Del. +, N.C. +, Va. +, W.Va. +, Vt. +, D.C +, Wis. +, Colo. +, Kans. +, Nebr. +, Okla. +, Idaho +, Mont. +, Oreg. +, Wash. +, Wyo. +, Pacific Islands (Hawaii) +, N.Mex. +, Utah +, Maine +, R.I. +, Fla. +, Ala. +, Ark. +, Ariz. +, Ga. +, Iowa +, Ill. +, Ind. +, Ky. +, La. +, Md. +, Mich. +, Minn. +, Mo. +, Miss. +, N.Dak. +, Nev. +, Ohio +, Pa. +, S.Dak. +, Tenn. +, Tex. +, Alaska +, S.C. +, Alta. +, B.C. +, Greenland +, Man. +, N.B. +, Nfld. and Labr. +, N.S. +, N.W.T. +, Nunavut +, Ont. +, P.E.I. +, Que. +, Sask. +  and Yukon +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
4 +  and 14 +
terete +  and laterally compressed +
1-9(11)-veined +
always shorter +  and usually shorter +
lanceolate +
subtending +
hairy +  and glabrous +
mucronate +  and acute +
unequal +
uncinate +
solid +  and hollow +
pubescent +  and glabrous +
rounded +  and lanceolate +
0.9 cm9 mm <br />0.009 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
herbaceous +  and coriaceous +
obtuse +  and truncate +
0 cm0 mm <br />0 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
concealed +  and prominent +
glabrous +  and pubescent +
2 +  and 7 +
2 +  and 1 +
hairy +  and glabrous +
well-developed +
reduced +
nodding +  and erect +
10 cm100 mm <br />0.1 m <br /> (24 cm240 mm <br />0.24 m <br />) +
dry +  and fleshy +
glabrous +, villous +  and pilose +
1 +  and 60 +
not viviparous +
elliptic +  and lanceolate terete +
1.6 cm16 mm <br />0.016 m <br /> (3.2 cm32 mm <br />0.032 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Bromus pumpellianus var. arcticus +, Bromus inermis subsp. pumpellianus +, Bromus inermis var. purpurascens +, Bromopsis pumpelliana var. arctica +, Bromopsis pumpelliana +  and Bromopsis inermis subsp. pumpellianus +
Bromus pumpellianus +
Bromus sect. Bromopsis +
species +
membranous +
0.75 cm7.5 mm <br />0.0075 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
plant +  and cespitose +
aquatic +  and terrestrial +