Arrhenatherum

P. Beauv.
Treatment appears in FNA Volume 24. Treatment on page 740.
 TaxonIllustrator 
FNA24 P285B Arrhenatherum pg 741.jpegArrhenatherum elatiusLinda Ann Vorobik
Hana Pazdírková

Plants perennial; cespitose, sometimes rhizomatous. Culms 30-200 cm, basal internodes occasionally globose. Sheaths open, not overlapping; auricles absent; ligules membranous, sometimes ciliate; blades flat or convolute. Inflorescences terminal, narrow panicles; branches spreading until after anthesis, then becoming loosely appressed to the rachises. Spikelets pedicellate, laterally compressed, with 2 florets, lower florets staminate, upper florets pistillate or bisexual, a rudimentary floret occasionally present distally; rachillas pubescent; disarticulation above the glumes, the florets usually falling together, rarely falling separately. Glumes unequal, hyaline, unawned; lower glumes less than 3/4 the length of the upper glumes, 1-veined or 3-veined; upper glumes 3-veined; calluses short, blunt, pubescent; lower lemmas membranous, 3-7-veined, acute, awned below midlength, awns twisted and geniculate; upper lemmas membranous to subcoriacous, glabrous or hairy, 7-veined, acute, usually unawned, sometimes awned from near the apices, awns short, straight, rarely awned similarly to the lower lemmas; paleas subequal to the lemmas, 2-veined, 2-keeled, keels scabrous or hairy, apices notched; lodicules 2, free, linear, membranous, glabrous, entire; anthers 3, 3.4-6.5 mm; ovaries pubescent. Caryopses shorter than the lemmas, concealed at maturity, not grooved, dorsally compressed to terete, hairy; hila long-linear, x = 7.

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 is a Mediterranean and eastern Asian genus of six species; one has become established in North America.

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

... more about "Arrhenatherum"
membranous +  and scarious +
0.34 cm3.4 mm <br />0.0034 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
notched +
Stephan L. Hatch +
P. Beauv. +
1 (?) +  and 3 (?) +
straight +
basal +  and terminal +
geniculate +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
not evident +
convolute +  and flat +
spikelike +
not branching +
ascending +  and erect +
30 cm300 mm <br />0.3 m <br /> (200 cm2,000 mm <br />2 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 +
unequal +
uncinate +
hairy +  and scabrous +
1-7(9)-veined +
lanceolate +  and ovate +
membranous +
inconspicuous +
lanceolate +
concealed +  and prominent +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
spikelike +
dry +  and fleshy +
brandenburg1985a +
not overlapping +
1 +  and 60 +
compressed +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (5 cm50 mm <br />0.05 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Arrhenatherum +
Poaceae tribe Poeae +
membranous +
hairy +  and glabrous +
membranous +  and subcoriacous +
parallel +  and converging +
plant +  and cespitose +
aquatic +  and terrestrial +