Calamagrostis ×acutiflora

(Schrad.) D.C.
Common names: Foerster's reedgrass Feather reedgrass
Treatment appears in FNA Volume 24. Treatment on page 721.

Plants often with robust sterile culms; densely cespitose, with rhizomes 1-3 cm long, about 2 mm thick. Culms 135-210 cm, smooth to slightly scabrous, usually unbranched; nodes about 3. Sheaths and collars smooth; ligules (1) 2-7 mm, lacerate; blades (5) 11-63 (71) cm long, (1) 1.5-7.5 (8) mm wide, flat or involute, usually scabrous, rarely smooth, adaxial surfaces glabrous or sparsely hairy. Panicles 15-30 cm long, 0.75-1 (3) cm wide, erect, contracted, pale green to purple; branches about 6 cm, slightly scabrous, longer branches with spikelets on the distal 2/3, shorter branches with spikelets to the base. Spikelets 4-5 mm; rachilla prolongations about 0.5 mm, hairs about 1.5 mm. Glumes keeled, mostly smooth, slightly scabrous only on the keels, veins usually obscure, apices acute; callus hairs 2-2.5 mm, 0.4-0.6 times as long as the lemmas, abundant; lemmas 3-3.5 mm, 1-1.5 mm shorter than the glumes; awns about 3.5 mm, attached to the lower 1/10 – 1/5 of the lemmas, exserted, slender, usually distinguishable from the callus hairs, bent; anthers not observed.

Discussion

Calamagrostis ×acutiflora is a hybrid of European origin that is now widely planted as an ornamental, especially in dry sites and gardens throughout northern North America. The parents are C. arundinacea (L.) Roth and C. epigejos (p. 710); the hybrids are seed-sterile.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

membranous +  and scarious +
hairy +  and glabrous +
Kendrick L. Marr +, Richard J. Hebda +  and Craig W. Greenef +
(Schrad.) D.C. +
1 (?) +  and 3 (?) +
straight +
attached +
exserted +  and lower +
distinguishable +
1/10 +  and 1/5 +
slender +
3.5 cm35 mm <br />0.035 m <br /> (?) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
11 cm110 mm <br />0.11 m <br /> (63 cm630 mm <br />0.63 m <br />) +
not evident +
involute +  and flat +
1.5mm;7.5mm +
appressed;more or less drooping +
spikelike +
0.4-0.6 times as long as the lemmas +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Foerster's reedgrass +  and Feather reedgrass +
ascending +  and erect +
scabrous +  and smooth to slightly +
135 cm1,350 mm <br />1.35 m <br /> (210 cm2,100 mm <br />2.1 m <br />) +
not woody +
Conn. +, N.J. +, N.Y. +, Wash. +, Va. +, Del. +, Oreg. +, Wis. +, Colo. +, D.C +, Utah +, W.Va. +, Pacific Islands (Hawaii) +, Kans. +, N.Dak. +, Nebr. +, S.Dak. +, Mass. +, Maine +, N.H. +, R.I. +, Vt. +, Wyo. +, N.Mex. +, La. +, N.C. +, Tenn. +, S.C. +, Pa. +, Ind. +, Ky. +, Calif. +, Nev. +, Iowa +, Mont. +, Alaska +, Ala. +, Ariz. +, Idaho +, Ill. +, Md. +, Mich. +, Minn. +, Ohio +, Ark. +, Ga. +, Alta. +, B.C. +, Greenland +, Man. +, N.B. +, Nfld. and Labr. +, N.S. +, N.W.T. +, Nunavut +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +  and Mo. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
sterile +  and bisexual +
compressed +
reduced +
subtending +
subequal +
membranous +
sparse +  and abundant +
uncinate +
1.5 cm15 mm <br />0.015 m <br /> (?) +
lanceolate +  and ovate +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
lacerate +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
membranous +
inconspicuous +
lanceolate +
concealed +  and prominent +
2 +  and 1 +
hairy +  and glabrous +
2-keeled +
pale green +  and purple +
15cm +  and 30cm +
spikelike +
0.75 cm7.5 mm <br />0.0075 m <br /> (1 cm10 mm <br />0.01 m <br />) +
dry +  and fleshy +
1 +  and 60 +
compressed +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Calamagrostis ×acutiflora +
Calamagrostis +
species +
membranous +
parallel +  and converging +
plant +  and cespitose +
aquatic +  and terrestrial +