Deschampsia cespitosa |
Deschampsia elongata |
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tuft hair grass |
hairgrass, slender hair grass |
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Habit | Plants perennial; loosely to tightly cespitose. | Plants perennial; densely cespitose. | ||||||||
Culms | (7) 35-150 cm, erect, not rooting at the lower nodes. |
(10)30-120 cm. |
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Leaves | mostly basal, sometimes forming a dense 10-35 cm tuft; sheaths glabrous; ligules 2-13 mm, scarious, decurrent, obtuse to acute; blades 5-30 cm long, usually at least some flat and 1-4 mm wide, the remainder folded or rolled and 0.5-1 mm in diameter, adaxial surfaces with 5-11 prominent ribs, ribs usually all papillose, scabridulous, or scabrous, sometimes puberulent, outer ribs sometimes more strongly so than the inner ribs. |
sometimes forming a basal tuft; sheaths glabrous; ligules 2.5-8(9) mm, acute to acuminate; blades 7-30 cm long, 0.2-2 mm wide, usually involute. |
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Panicles | 8-30(40) cm, 4-30 cm wide, usually open and pyramidal, sometimes contracted and ovate; branches straight to slightly flexuous, usually strongly divergent, sometimes strongly ascending, lower branches often scabridulous or scabrous, particularly distally, with not or only moderately imbricate spikelets. |
5-30(35) cm long, 0.5-1.5(2) cm wide, erect or nodding; branches erect to ascending. |
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Spikelets | 2.5-7.6 mm, ovate to V-shaped, laterally compressed, usually bisexual, sometimes viviparous, bisexual spikelets usually with 2(3) florets, rarely with 1. |
3-6.7 mm, bisexual, narrowly V-shaped, appressed to the branches. |
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Glumes | lanceolate, acute; lower glumes 2.7-7 mm, entire, 1-3-veined, midvein sometimes scabridulous, at least distally; upper glumes 2-7.5 mm, 1-3-veined, lanceolate, midvein smooth or wholly or partly scabridulous; callus hairs 0.2-2.3 mm; lemmas 2-5(7) mm, smooth, shiny, glabrous, usually purple over less than 1/2 their surface, purple or green proximally, if green, often with a purple band about midlength, usually green or pale distally, usually awned, awns (0.5)1-8 mm, attached from near the base to about midlength, straight or geniculate, sometimes exceeding the glumes; anthers 1.5-3 mm. |
equaling or exceeding the florets, narrowly lanceolate, usually pale green, sometimes purple-tipped, 3-veined, acuminate; lower glumes (3)3.2-5.5(6.7) mm; upper glumes (3)3.1-5.4(6) mm; callus hairs 0.3-1.15 mm; lemmas 1.7-4.3 mm, smooth, shiny, glabrous, apices weakly toothed or erose, awns 1.5-5.5(6) mm, straight to slightly geniculate, attached from slightly below to slightly above the middle of the lemma, exceeding the florets by 1-2.5 mm; anthers 0.3-0.5(0.7) mm. |
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Caryopses | 0.5-1 mm. |
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The | voucher specimens for these counts have not been examined. |
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2n | = 18, 24, 25, 26-28, about 39, 52. |
= 26. |
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Deschampsia cespitosa |
Deschampsia elongata |
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Distribution |
AK; AZ; CA; CO; CT; ID; IL; IN; KY; MA; MD; ME; MI; MN; MT; NC; ND; NH; NJ; NM; NV; NY; OH; OR; PA; RI; SD; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; SK; YT; Greenland
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AK; AZ; CA; ID; MA; ME; MT; NM; NV; OR; SC; UT; WA; WY; AB; BC; NU; YT
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Discussion | Deschampsia cespitosa is circumboreal in the Northern Hemisphere, and also grows in New Zealand and Australia. It is an attractive taxon that grows in wet meadows and bogs, and along streams and lakes, from sea level to over 3000 m in cool-temperate, but not arctic, habitats. There are widely varying opinions concerning the taxonomic treatment of Deschampsia cespitosa. Tsvelev, Aiken, Murray, and Elven (per Murray, pers. com. 2005) recommend a narrow circumscription, and consider D. cespitosa to be introduced and mostly ruderal in regions other than Europe and western Siberia. Chiapella and Probatova (2003) adopted a much broader interpretation of D. cespitosa, treating many of the species recognized in, for example, Tsvelev (1995) as subspecies. There have been no interdisplinary, global studies of the complex. The circumscription adopted here is narrower than has been customary in North America. Some of the distribution records shown, particularly those from the northern part of the region, may reflect the broad interpretation of the species. Lawrence (1945) demonstrated that, in western North America, Deschampsia cespitosa exhibits both ecotypic differentiation and a high degree of plasticity. The following three subspecies intergrade. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Deschampsia elongata grows in moist to wet habitats, from near sea level to alpine elevations, from Alaska and the Yukon south to northern Mexico and east to Montana, Wyoming, and Arizona. It also grows, as a disjunct, in Chile. The records from Maine and Colorado probably represent introductions. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 24, p. 626. | FNA vol. 24, p. 631. | ||||||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Deschampsia | Poaceae > subfam. Pooideae > tribe Poeae > Deschampsia | ||||||||
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Subordinate taxa | ||||||||||
Synonyms | D. caespitosa var. genuina, D. caespitosa var. arctica, D. caespitosa | |||||||||
Name authority | (L.) P. Beauv. | (Hook.) Munro | ||||||||
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