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tuft hair grass

deschampsie naine

Habit Plants perennial; loosely to tightly cespitose. Plants perennial; usually densely cespitose.
Culms

(7) 35-150 cm, erect, not rooting at the lower nodes.

5-70 cm, erect or strongly geniculate at the first node, 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.

mostly basal, sometimes forming a dense, moss-like tuft 5-20 cm in diameter;

sheaths smooth, glabrous;

ligules 1.5-8 mm, acute;

blades 0.5-8 cm long, usually strongly rolled and 0.5-1.3 mm in diameter, rarely flat and to 1.5(2) mm wide, abaxial surfaces smooth, adaxial surfaces with 3-5(6) ribs, ribs smooth, the outer ribs sometimes scabrous.

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.

3.5-17 cm long, 1.5-9 cm wide, usually open and pyramidal, sometimes closed and ovate;

branches 0.5-6 cm, spreading to reflexed, flexuous, 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.

3.5-5.2 mm, shiny, purplish, with 2(3) florets.

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.

lanceolate, sometimes purplish over the proximal 1/2, acute to acuminate;

lower glumes 2.7-4.8 mm, 0.8-0.9 times the length of the spikelets, 1-3-veined, veins smooth;

upper glumes 3-5 mm, equaling or exceeding the lowest floret, 1-5-veined;

callus hairs 0.3-1 mm;

lemmas 2-4 mm, smooth, shiny, glabrous, sometimes purplish distally, apices rounded or truncate, erose, awns 0.8-2.5 mm, arising at or below midlength, straight, slender, only slightly or not exserted;

anthers 0.7-2.5 mm.

Caryopses

0.5-1 mm.

The

voucher specimens for these counts have not been examined.

2n

= 18, 24, 25, 26-28, about 39, 52.

= 26, 28, 36, ca. 39.

Deschampsia cespitosa

Deschampsia cespitosa

Distribution
from FNA
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
[WildflowerSearch map]
from USDA
[WildflowerSearch map]
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 sukatschewii is a circumboreal species that extends from northern Russia through Alaska, northern Canada, and Greenland to Svalbard, and southward in the Rocky Mountains to Nevada and Utah. It ranges from short plants that form dense, mossy tufts on the Arctic coast to larger plants in subalpine and alpine habitats of the Rocky Mountains that have frequently been included in D. cespitosa.

Arctic taxonomists recognize two subspecies of Deschampsia sukatschewii in arctic North America: the amphiberingian subsp. orientalis (Hulten) Tzvelev that extends to the northern coast of Alaska and the western Northwest Territories; and subsp. borealis (Trautv.) Tzvelev, which is circumpolar in the arctic. Chiapella and Probatova (2003) treated these two subspecies, and subsp. sukatschewii, as subspecies of D. cespitosa. Efforts to circumscribe infraspecific taxa of D. sukatschewii for this treatment failed.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Panicles contracted at anthesis, the branches appressed to ascending; glumes 4.5-5.8 mm long, midvein of the lower glumes scabrous distally
subsp. holciformis
1. Panicles open at anthesis, the branches strongly divergent to drooping; glumes 2-7.5 mm long; midvein of the lower glumes smooth or scabridulous distally.
→ 2
2. Plants often glaucous; glumes 4.4-7.5 mm long; awns usually exceeding the lemmas; plants of the northwest coast of North America
subsp. beringensis
2. Plants not glaucous; glumes 2-6 mm long; awns exceeded by or exceeding the lemmas; plants widespread in North America
subsp. cespitosa
Source FNA vol. 24, p. 626. FNA vol. 24, p. 629.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Deschampsia Poaceae > subfam. Pooideae > tribe Poeae > Deschampsia
Sibling taxa
D. alpina, D. brevifolia, D. danthonioides, D. elongata, D. flexuosa, D. mackenzieana, D. sukatschewii
D. alpina, D. brevifolia, D. cespitosa, D. danthonioides, D. elongata, D. flexuosa, D. mackenzieana
Subordinate taxa
D. cespitosa subsp. beringensis, D. cespitosa subsp. cespitosa, D. cespitosa subsp. holciformis
Synonyms D. caespitosa var. genuina, D. caespitosa var. arctica, D. caespitosa D. brevifolia var. pumila, D. borealis, D. arctica var. pumila
Name authority (L.) P. Beauv. (Popl.) Roshev.
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