Deschampsia cespitosa |
Deschampsia alpina |
|||||||||
---|---|---|---|---|---|---|---|---|---|---|
tuft hair grass |
alpine hairgrass, deschampsie alpine, hairgrass |
|||||||||
Habit | Plants perennial; loosely to tightly cespitose. | Plants perennial; densely cespitose. | ||||||||
Culms | (7) 35-150 cm, erect, not rooting at the lower nodes. |
8-45(65) cm, smooth, glabrous. |
||||||||
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. |
forming a basal tuft; sheaths smooth, glabrous; ligules 1.5-7.5 mm, glabrous, acute to acuminate, entire; blades 2-8 cm long, 0.5-2 mm wide, usually folded or flat, sometimes some loosely involute, both surfaces glabrous, smooth. |
||||||||
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. |
(4)8-16 cm; branches 2-8 cm long (excluding the blades of bulbous florets), straight, ascending, smooth. |
||||||||
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. |
usually viviparous, their length varying with age, rarely bisexual and 4-6.3 mm. |
||||||||
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. |
subequal, exceeding the lowest floret in sexual spikelets, keels smooth, apices acuminate; callus hairs about 0.8 mm; lemmas 5-7 mm, smooth, shiny, glabrous, unawned or awned, awns to 4 mm, straight, attached from below midlength to near the apices; paleas vestigial or absent. |
||||||||
Caryopses | 0.5-1 mm. |
|||||||||
The | voucher specimens for these counts have not been examined. |
|||||||||
2n | = 18, 24, 25, 26-28, about 39, 52. |
= 52, 56. |
||||||||
Deschampsia cespitosa |
Deschampsia alpina |
|||||||||
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
|
NF; NU; QC; Greenland |
||||||||
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 alpina grows in damp, rocky places, on calcareous substrates with low organic content, in Greenland and northeastern Canada and, outside the Flora region, in the mountains of Scandinavia and Russia in the Kola Peninsula and Novaya Zemlya. Plants of D. alpina differ from viviparous plants of D. cespitosa in having smooth, rather than scabrous, panicle branches (Murray, pers com. 2005). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||
Key |
|
|||||||||
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 | D. caespitosa subsp. alpina | ||||||||
Name authority | (L.) P. Beauv. | (L.) Roem. & Schult. | ||||||||
Web links |
|