Deschampsia cespitosa subsp. cespitosa

Common names: Tufted hairgrass Deschampsie cespiteuse
Synonyms: Deschampsia caespitosa var. glauca
Treatment appears in FNA Volume 24. Treatment on page 628.
Please click on the illustration for a higher resolution version.
Illustrator: Cindy Roché

Copyright: Utah State University

Plants densely cespitose, not glaucous. Culms (7) 35-150 cm. Ligules 2-8 mm; blades 5-25 cm long, 1.5-3.5 mm wide when flat. Panicles 8-30 cm long, 4-30 cm wide, open, nodding, pyramidal; branches, both primary and secondary, usually divergent, usually sparsely to moderately scabridulous or scabrous, sometimes smooth. Spikelets 2.5-7 mm, not to slightly imbricate. Glumes subequal to the distal floret, lengths often less than 5 times widths; lower glumes 2.5-5 mm, midveins smooth or scabridulous distally; upper glumes 2-6 mm; lemmas 2-4 mm, purple and/or green proximally, green to gold distally, the purple portion usually less than 1/2 the surface area, awns 1-8 mm, usually attached near the base, sometimes attached near midlength, straight or geniculate, exceeded by or exceeding the distal floret; anthers 1.5-2 mm.

Discussion

Deschampsia cespitosa subsp. cespitosa is treated here as a circumboreal taxon that is most prevalent in boreal and temperate North America, growing at 0-3000 m; many reports from arctic and alpine North America refer to what are treated here as D. sukatschewii or D. brevifolia. Even with this narrower interpretation, D. cespitosa is highly polymorphic. Plants with long awns are more prevalent in western North America but, within that region, do not appear to show any geographic or ecological preference (Lawrence 1945). Larger plants are difficult to distinguish from D. cespitosa subsp. beringensis. The morphological, geographic, and ecological boundaries between D. cespitosa subsp. cespitosa and subsp. beringensis need further study.

Many cultivars of Deschampsia cespitosa subsp. cespitosa have been developed. At one time, the most frequently cultivated plants were distinguished by their combination of large (20-40 cm) panicles and small (2.5-4 mm) spikelets, and were called D. cespitosa var. parviflora (Thuill.) Coss. & Germ, or D. cespitosa subsp. parviflora (Thuill.) K. Richt. Such plants are treated here as one part of the spectrum of variation in subsp. cespitosa.

The name Deschampsia cespitosa var. glauca (Hartm.) Lindm. has been applied in eastern North America to glaucous plants less than 75 cm tall, with spikelets only 3-4.5 mm long. Unfortunately, the name is illegitimate; there is no legitimate name available for such plants.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

52 +, 39 +, 26 +  and 28 +
membranous +  and scarious +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
2-4-toothed +
Mary E. Barkworth +
(L.) P. Beauv. +
1 (?) +  and 3 (?) +
0.5 cm5 mm <br />0.005 m <br /> (?) +
straight +
attached +
subapical +
geniculate +
0.1 cm1 mm <br />0.001 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
midlength +
swelling +
5 cm50 mm <br />0.05 m <br /> (25 cm250 mm <br />0.25 m <br />) +
not evident +
rolled +  and folded +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
straight +  and slightly flexuous +
scabridulous +
spikelike +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
Tufted hairgrass +  and Deschampsie cespiteuse +
not rooting +
35 cm350 mm <br />0.35 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
not woody +
Wash. +, Va. +, Wis. +, W.Va. +, Conn. +, Mass. +, Maine +, N.H. +, N.Y. +, R.I. +, Vt. +, Wyo. +, N.J. +, N.Mex. +, N.C. +, Pa. +, Calif. +, Nev. +, Colo. +, Alaska +, Ill. +, Ind. +, Ariz. +, Idaho +, Alta. +, B.C. +, Greenland +, Man. +, N.B. +, Nfld. and Labr. +, N.S. +, N.W.T. +, Nunavut +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Md. +, Ohio +, Utah +, Minn. +, Mich. +, N.Dak. +, S.Dak. +, Mont. +, Ky. +  and Oreg. +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
1 +  and 2 +
viviparous +  and bisexual +
compressed +
reduced +
3-veined +  and 1-veined +
shorter or longer +
subtending +
acute +  and lanceolate +
subequal +
uncinate +
(3)5-7-veined +
green +  and gold +
rounded +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
obtuse +  and acute +
0.2 cm2 mm <br />0.002 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
inconspicuous +
lanceolate +  and ovatelanceolate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
scabridulous +  and smooth +
concealed +  and prominent +
2 +  and 1 +
well-developed +
2-keeled +
40 cm400 mm <br />0.4 m <br /> (?) +
8cm +  and 30cm +
pyramidal +
8 cm80 mm <br />0.08 m <br /> (30 cm300 mm <br />0.3 m <br />) +
4 cm40 mm <br />0.04 m <br /> (30 cm300 mm <br />0.3 m <br />) +
dry +  and fleshy +
5 +  and 11 +
1 +  and 60 +
bisexual +  and viviparous +
compressed +, ovate +  and v-shaped +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
0 (?) +  and 1/2 (?) +
Deschampsia caespitosa var. glauca +
Deschampsia cespitosa subsp. cespitosa +
Deschampsia cespitosa +
subspecies +
membranous +
10 cm100 mm <br />0.1 m <br /> (35 cm350 mm <br />0.35 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
parallel +  and converging +
stoloniferous +  and rhizomatous +
plant +  and cespitose +
aquatic +  and terrestrial +