Deschampsia cespitosa |
Deschampsia flexuosa |
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tuft hair grass |
Appalachian hairgrass, common hairgrass, crinkled hairgrass, deschampsie flexueuse, wavy 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. |
30-80 cm, erect or geniculate at the base, usually with 2 nodes. |
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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. |
mostly basal, sometimes forming a basal tuft; sheaths smooth, glabrous; ligules 1.5-3.6 mm, rounded to acute; blades 12-25 cm long, strongly rolled, 0.3-0.5 mm in diameter, abaxial surfaces smooth or scabridulous, glabrous or hairy, often scabridulous or hairy proximally and essentially smooth and glabrous distally, adaxial surfaces scabrous, flag leaf blades 5-8 cm. |
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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. |
5-15 cm long, (2)4-12 cm wide, narrow to open, often nodding; branches ascending to spreading, flexuous, smooth or scabridulous. |
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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. |
4-7 mm, ovate or U-shaped. |
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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. |
exceeded by or subequal to the adjacent florets, 1-veined, acute; lower glumes 2.7-4.5 mm; upper glumes 3.5-5 mm; callus hairs to 1 mm; lemmas 3.3-5 mm, scabridulous or puberulent, hairs to 0.1 mm, apices acute, erose to 4-toothed, awns 3.7-7 mm, attached near the base of the lemma, strongly geniculate, geniculation below the lemma apices, distal segment 2.5-4.5 mm, pale; anthers 2-3 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. |
= 14, 26, 28, 32, 42. |
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Deschampsia cespitosa |
Deschampsia flexuosa |
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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; AL; AR; CT; DC; DE; GA; KY; MA; MD; ME; MI; MN; NC; ND; NH; NJ; NY; OH; OK; PA; RI; SC; TN; VA; VT; WI; WV; BC; NB; NL; NS; ON; PE; QC; Greenland
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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 flexuosa grows on dry, often rocky slopes, and in woods and thickets, often in disturbed sites. In the Flora region, it is primarily eastern in distribution, with records from west of the Great Lakes and Appalachians probably being introductions. It is also known from Mexico, Central America, South America, Borneo, the Philippines, and New Zealand. (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 | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | D. caespitosa var. genuina, D. caespitosa var. arctica, D. caespitosa | Lerchenfeldia flexuosa subsp. montana, Aira flexuosa | ||||||||
Name authority | (L.) P. Beauv. | (L.) Trin. | ||||||||
Web links |
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