Arrhenatherum elatius

(L.) P. Beauv. ex J. Presl & C. Presl
Common names: Tall oatgrass Fenasse Fromental
Introduced
Synonyms: Arrhenatherum elatius var. biaristatum Biaristatum
Treatment appears in FNA Volume 24. Treatment on page 742.

Plants loosely cespitose, sometimes rhizomatous, rhizomes to 3 mm thick. Culms 50-140 (180) cm, erect, glabrous, unbranched, basal internodes swollen or not; nodes usually glabrous, occasionally puberulent to densely hairy. Sheaths smooth; ligules 1-3 mm, obtuse to truncate, usually ciliate; blades 5-32 cm long, (1) 3-8 (10) mm wide, flat, usually glabrous, rarely shortly pilose, sometimes scabrous. Panicles 7-30 (36) cm long, 1-6 (10) cm wide, green, shiny, becoming stramineous, sometimes purple-tinged; branches 15-20 mm, ascending to divergent, verticillate, usually spikelet-bearing to the base; pedicels 1-10 mm. Spikelets 7-11 mm; rachillas stout, internodes to 0.7 mm, prolongations 1.2-2 mm, slender, apices often with a small, club-shaped rudiment. Glumes lanceolate to elliptic; lower glumes 4-7 mm; upper glumes 7-10 mm; callus hairs to 3.7 mm; lemmas (4) 7-10 mm, apices bifid; awns of lower lemmas 10-20 mm, twisted below, often with alternating light and dark bands; awns of upper lemmas absent or to 5 mm and arising just below the apices, rarely to 15 mm and arising from above the middle; paleas 0.5-1 mm shorter than the lemmas, acute; anthers 3.6-5 (6) mm. Caryopses 4-5 mm long, about 1.2 mm wide, ellipsoid, densely hairy, yellowish. 2n = 14, 28, 42.

Distribution

Conn., N.J., N.Y., Wash., Del., D.C., Wis., W.Va., Pacific Islands (Hawaii), Mass., Maine, N.H., R.I., Vt., B.C., N.B., Nfld. and Labr. (Labr.), N.S., Ont., Que., Wyo., N.Mex., La., N.C., Nebr., Tenn., Pa., Calif., Nev., Va., Colo., Md., Alaska, Ala., Ark., Ill., Ga., Ind., Iowa, Ariz., Idaho, Mont., Oreg., Ohio, Utah, Mo., Minn., Mich., Kans., Miss., S.Dak., Ky.

Discussion

Arrhenatherum elatius is grown as a forage grass, and yields palatable hay; it does not withstand heavy grazing. It readily escapes from cultivation, and can be found in mesic to dry meadows, the edges of woods, streamsides, rock outcrops, and disturbed areas such as fields, pastures, fence rows, and roadsides. Variegated forms, with the leaves striped green and white or yellow, are cultivated as ornamentals. There are two subspecies, both of which have been found in the Flora region. Plants in which both lemmas have long, geniculate awns have been called A. elatius var. biaristatum (Peterm.) Peterm., but do not merit formal taxonomic recognition.

Arrhenatherum elatius (L.) P. Beauv. ex J. Presl & C. Presl subsp. elatius has glabrous nodes and basal internodes 2-4 mm thick. It is more common than Arrhenatherum elatius subsp. bulbosum (Willd.) Schiibl. 8c G. Martens, which has densely hairy nodes, and swollen basal internodes 5-10 mm thick. While both can be weedy, the latter subspecies is especially difficult to control in cultivated fields, as tilling the soil spreads the swollen internodes, which then propagate vegetatively.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number."-veined" is not declared as a valid unit of measurement for this property.

... more about "Arrhenatherum elatius"
42 +, 28 +  and 14 +
membranous +  and scarious +
6 cm60 mm <br />0.06 m <br /> (?) +
0.36 cm3.6 mm <br />0.0036 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Stephan L. Hatch +
(L.) P. Beauv. ex J. Presl & C. Presl +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
geniculate +
0 cm0 mm <br />0 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
keeled +  and rounded +
dark +  and light +
not +  and swollen +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
5 cm50 mm <br />0.05 m <br /> (32 cm320 mm <br />0.32 m <br />) +
not evident +
pilose +  and glabrous +
convolute +  and flat +
3mm;8mm +
verticillate +  and divergent +
spikelike +
0 cm0 mm <br />0 m <br /> (0.37 cm3.7 mm <br />0.0037 m <br />) +
Tall oatgrass +, Fenasse +  and Fromental +
50 cm500 mm <br />0.5 m <br /> (140 cm1,400 mm <br />1.4 m <br />) +
not woody +
Conn. +, N.J. +, N.Y. +, Wash. +, Del. +, D.C. +, Wis. +, W.Va. +, Pacific Islands (Hawaii) +, Mass. +, Maine +, N.H. +, R.I. +, Vt. +, B.C. +, N.B. +, Nfld. and Labr. (Labr.) +, N.S. +, Ont. +, Que. +, Wyo. +, N.Mex. +, La. +, N.C. +, Nebr. +, Tenn. +, Pa. +, Calif. +, Nev. +, Va. +, Colo. +, Md. +, Alaska +, Ala. +, Ark. +, Ill. +, Ga. +, Ind. +, Iowa +, Ariz. +, Idaho +, Mont. +, Oreg. +, Ohio +, Utah +, Mo. +, Minn. +, Mich. +, Kans. +, Miss. +, S.Dak. +  and Ky. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
rudimentary +
sterile +  and bisexual +
compressed +
reduced +
shorter or longer +
subtending +
lanceolate +  and elliptic +
unequal +
uncinate +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
hairy +  and scabrous +
1-7(9)-veined +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
lanceolate +  and ovate +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
obtuse to truncate +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
membranous +
inconspicuous +
lanceolate +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
concealed +  and prominent +
occasionally puberulent +  and densely hairy +
2 +  and 1 +
well-developed +
subequal +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
purple-tinged +, stramineous +  and green +
7cm +  and 30cm +
spikelike +
1 cm10 mm <br />0.01 m <br /> (6 cm60 mm <br />0.06 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (1 cm10 mm <br />0.01 m <br />) +
dry +  and fleshy +
not overlapping +
Introduced +
1 +  and 60 +
compressed +
0.7 cm7 mm <br />0.007 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Arrhenatherum elatius var. biaristatum +  and Biaristatum +
Arrhenatherum elatius +
Arrhenatherum +
species +
membranous +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
hairy +  and glabrous +
membranous +  and subcoriacous +
parallel +  and converging +
plant +  and cespitose +
aquatic +  and terrestrial +