Plants usually perennial, sometimes annual; cespitose or tufted. Culms 5–140 cm, hollow, erect. Leavesusually mainly basal, often forming a dense tuft; sheaths open; auricles absent; ligules membranous, decurrent, rounded to acuminate; blades often all or almost all tightly rolled or folded and some flat, sometimes most flat, others rolled or folded. Inflorescences terminal panicles, open or contracted; disarticulation above the glumes, beneath the florets. Spikelets 3–9 mm, with 2(3) florets in all or almost all spikelets, florets usually bisexual, sometimes viviparous; rachillas hairy, usually prolonged more than 0.5 mm beyond the base of the distal floret, sometimes terminating in a highly reduced floret. Glumes subequal to unequal, usually exceeding the adjacent florets, often exceeding all florets, 1- or 3-veined, acute to acuminate; calluses antrorsely strigose; lemmas obscurely (3)5–7-veined, rounded over the back, apices truncate-erose to 2–4-toothed, awned, awns usually attached on the lower 1/2 of the lemmas, occasionally subapical, straight to strongly geniculate, slightly to strongly twisted proximally, straight distally; paleasshorter than the lemmas, 2-keeled, keels often scabrous; lodicules 2, lanceolate to ovate-lanceolate, usually entire; anthers 3; ovaries glabrous; styles 2. Caryopses oblong; embryos about 1/4 the length of the caryopses. x = 7. Named for Louise Auguste Deschamps (1765–1842), a French naturalist.

Deschampsia includes 20–40 species. It is best represented in the Americas and Eurasia, but it grows in cool, damp habitats throughout the world. Seven species are native to the Flora region; none of the remaining species have been introduced.

Deschampsia differs from Vahlodea, which it used to include, in having primarily basal, rather than primarily cauline, leaves, and hairy rachillas that extend more than 0.5 mm beyond the base of the distal floret in a spikelet. Trisetum differs from Deschampsia primarily in its more acute, bifid lemmas, and in having awns that are inserted at or above the midpoint of the lemmas. In Deschampsia, the awns are usually inserted near the base.

Because the treatments of Deschampsia brevifolia and D. sukatschewii were revised shortly before going to press, the maps are preliminary, particularly with respect to the Canadian distribution of these two species.

Lemma length, awn attachment, and awn length should be examined on the lower florets within the spikelets. The upper florets often have shorter lemmas, and shorter awns that are attached higher on the back than those of the lower florets.

SELECTED REFERENCES Aiken, S.G., L.L. Consaul, and M.J. Dallwitz. 1995 on. Grasses of the Canadian Arctic Archipelago: Descriptions, illustrations, identification and information retrieval. http://www.mun.ca/biology/delta/arcticf/poa/index.htm; Chiapella, J. 2000. The Deschampsia cespitosa complex in central and northern Europe: A morphological analysis. Bot. J. Linn. Soc. 134:495–512; Chiapella, J. and N.S. Probatova. 2003. The Deschampsia cespitosa complex (Poaceae: Aveneae) with special reference to Russia. Bot. J. Linn. Soc. 142:213–228; Clarke, G.C.S. 1980. Deschampsia Beauv. Pp. 225–227 in T.G. Tutin, V.H. Heywood, N.A. Burges, D.M. Moore, D.H. Valentine, S.M. Walters, and D.A. Webb (eds.). Flora Europaea, vol. 5. Cambridge University Press, Cambridge, England. 452 pp.; Hultén, E. 1960. Flora of the Aleutian Islands and Westernmost Alaska Peninsula with Notes on the Flora of Commander Islands. J. Cramer, Weinheim, Germany. 376 pp.; Kawano, S. 1966. Biosystematic studies of the Deschampsia caespitosa complex with special reference to the karyology of Icelandic populations. Bot. Mag. (Tokyo) 79:293–307; Lawrence, W.E. 1945. Some ecotypic relations of Deschampsia caespitosa. Amer. J. Bot. 32:298–314; McLachlan, K.I., S.G. Aiken, L.P. Lefkovitch, and S.A. Edlund. 1989. Grasses of the Queen Elizabeth Islands. Canad. J. Bot. 67:2088–2105; Tsvelev, N.N. 1995. Deschampsia. Pp. 150–163 in J.G. Packer (ed., English edition). Flora of the Russian Arctic, vol. 1, trans. G.C.D. Griffiths. University of Alberta Press, Edmonton, Alberta, Canada [English translation of A.I. Tolmachev (ed.). 1964. Arkticheskaya Flora SSSR, vol. 2. Nauka, Leningrad [St. Petersburg], Russia].