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pine reed grass, pinegrass

Rainier reedgrass, Tacoma reedgrass

Habit Plants sometimes with sterile culms; sometimes loosely cespitose, usually with rhizomes 15+ cm long, 1.5-2 mm thick. Plants without sterile culms; cespitose, sometimes densely so, usually without rhizomes, sometimes with rhizomes about 2 cm long, 2-3 mm thick.
Culms

(50)60-100(105) cm, unbranched, usually smooth, rarely slightly scabrous beneath the panicles;

nodes (1)2-3(4).

(20)30-55(95) cm, unbranched, smooth or slightly scabrous beneath the panicles;

nodes (1)2(5).

Sheaths

smooth or slightly scabrous;

collars often hairy, rarely glabrous;

ligules (2)3-5(6) mm, truncate to obtuse, often lacerate;

blades (6)8-40(42) cm long, (1)2-5(8) mm wide, usually flat, abaxial surfaces smooth or slightly scabrous, adaxial surfaces smooth or scabrous, glabrous or sparsely hairy.

and collars smooth or slightly scabrous;

ligules (3)3.5-5.5(6) mm, usually truncate to obtuse, usually entire, sometimes lacerate;

blades (6)7-14(30) cm long, (1.5)2-2.5(4) mm wide, flat, abaxial surfaces usually smooth, rarely slightly scabrous, adaxial surfaces usually slightly scabrous, rarely smooth, glabrous or sparsely hairy.

Panicles

(5)6-15(25) cm long, (0.7)1.5-2(2.7) cm wide, contracted to somewhat open, erect, usually greenish, infrequently purplish;

branches (1.2)2-4(10) cm, usually slightly scabrous, rarely densely long-scabrous, spikelet-bearing to the base.

(5)7-10(18) cm long, (0.5)1-2(3) cm wide, loosely contracted, sometimes open, erect to slightly nodding, shiny green and purple;

branches (2)2.3-4(6) cm, scabrous, usually spikelet-bearing on the distal 2/3, sometimes to the base.

Spikelets

(3)4-4.5(5.5) mm;

rachilla prolongations 0.6-1.5(2) mm, hairs 1.2-2 mm.

(4)6-6.5(7) mm;

rachilla prolongations 1.5-2(2.5) mm, hairs (1.5)2(3) mm.

Glumes

rounded to slightly keeled, mostly smooth, keels rarely slightly scabrous, lateral veins usually obscure, rarely prominent, apices acute;

callus hairs (0.5)1-1.5(2.5) mm, 0.2-0.5(0.7) times as long as the lemmas, sparse;

lemmas 2.5-3.5(4) mm, (0.5)1-2 mm shorter than the glumes;

awns 2.8-3.5(4.5) mm, usually attached to the lower 1/5 of the lemmas, rarely higher, exserted, stout and readily distinguished from the callus hairs, strongly bent;

anthers (1)1.3-2(2.6) mm.

often green with a purple patch at the base, keeled, keels smooth or sparsely scabrous on the distal 1/2, lateral veins usually prominent, apices usually acute, sometimes short-acuminate, not twisted;

callus hairs (1.2)2(2.5) mm, (0.3)0.4-0.5(0.6) times as long as the lemmas, abundant;

lemmas (3.5)4-5(5.5) mm, (0.5)1.5-2(3) mm shorter than the glumes;

awns (5.5)7-8.5(10) mm, attached to the lower 1/10-1/3 of the lemmas, exserted more than 2 mm, easily distinguished from the callus hairs, strongly bent;

anthers (1)2-3(3.5) mm.

2n

= 28, 42, 56.

= unknown.

Calamagrostis rubescens

Calamagrostis tacomensis

Distribution
from FNA
CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC; MB; SK
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[BONAP county map]
from FNA
OR; WA
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[BONAP county map]
Discussion

Calamagrostis rubescens grows at 50-2800 m, usually in open montane pine or aspen forests and parklands, infrequently in sagebrush steppes, chaparral, and meadows. It is primarily a species of interior western North America, although it reaches the Pacific coast in southern California. The distribution extends from central British Columbia and Alberta east to the Cypress Hills of eastern Alberta and the Pasquia and Cub hills of Saskatchewan, south to western California, Nevada, northeastern Utah, and central Colorado. It is considered threatened in Saskatchewan.

Calamagrostis rubescens is similar to C. koelerioides (p. 721). The two have traditionally been distinguished by the presence of hairs on the leaf collars of C. rubescens, and their absence from C. koelerioides; a more reliable differentiation is the shorter lemmas, glumes, and awns of C. rubescens. Calamagrostis rubescens and C. porteri (p. 721) appear to be closely related. They may be part of the general phenomenon of eastern and western vicariants.

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

Calamagrostis tacomensis grows on montane to alpine slopes in dry or wet meadows, seeps, rocky talus slopes, and cliff crevices, at 400-2200 m. It grows only in the mountains of western Washington and in the Steens Mountains of southeastern Oregon. It reaches its highest known elevations in the Steens Mountains.

This species has previously been identified as either Calamagrostis purpurascens (p. 710) (C.L. Hitchcock et al. 1969) or C. sesquiflora (p. 714) (Kawano 1965). It differs from C. purpurascens in having glabrous leaves, generally longer awns and inflorescence branches, and smoother glumes. It differs from C. sesquiflora in having narrower leaves, callus hairs that are longer relative to the lemmas, longer inflorescence branches, and glume apices that are not twisted, as well as in often preferring drier habitats.

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

Source FNA vol. 24. FNA vol. 24, p. 716.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Calamagrostis Poaceae > subfam. Pooideae > tribe Poeae > Calamagrostis
Sibling taxa
C. bolanderi, C. breweri, C. cainii, C. canadensis, C. cinnoides, C. deschampsioides, C. epigejos, C. foliosa, C. howellii, C. koelerioides, C. lapponica, C. montanensis, C. muiriana, C. nutkaensis, C. ophitidis, C. perplexa, C. pickeringii, C. porteri, C. purpurascens, C. scopulorum, C. sesquiflora, C. stricta, C. tacomensis, C. tweedyi, C. ×acutiflora
C. bolanderi, C. breweri, C. cainii, C. canadensis, C. cinnoides, C. deschampsioides, C. epigejos, C. foliosa, C. howellii, C. koelerioides, C. lapponica, C. montanensis, C. muiriana, C. nutkaensis, C. ophitidis, C. perplexa, C. pickeringii, C. porteri, C. purpurascens, C. rubescens, C. scopulorum, C. sesquiflora, C. stricta, C. tweedyi, C. ×acutiflora
Name authority Buckley K.L. Marr & Hebda
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