The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

pine reed grass, pinegrass

ditch reedgrass, Jones' 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; loosely cespitose, with rhizomes to 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).

(40)50-92 cm, sometimes branched, sparsely to densely scabrous;

nodes 2-3.

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 scabrous;

ligules (3)4-7(9) mm, obtuse, lacerate;

blades 10-38 cm long, (2)3-4(7) mm wide, flat, scabridulous, adaxial surfaces 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.

(4)7-16(18) cm long, (0.7)1.1-2(3) cm wide, nodding, contracted, pale green to purple-tinged;

branches 1-5(6.5) cm, sparsely to densely scabrous, usually spikelet-bearing 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)4.5-6 mm;

rachilla prolongations 1-2 mm, hairy throughout, hairs 1.5-2.5 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.

keeled, mostly smooth, keels slightly scabrous distally, lateral veins obscure, apices acuminate;

callus hairs 2-3 mm, 0.5-0.6 times as long as the lemmas, somewhat sparse;

lemmas 3.5-5 mm, 0.5-1.5 mm shorter than the glumes;

awns (0.5)1-1.5(2) mm, attached to the upper 2/5 of the lemmas, not exserted, slender, straight, easily overlooked when short;

anthers (1.8)2-2.7(3) mm.

2n

= 28, 42, 56.

= 28.

Calamagrostis rubescens

Calamagrostis scopulorum

Distribution
from FNA
CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC; MB; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CO; MT; NM; UT; WY
[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 scopulorum grows on canyon slopes and wash bottoms, and in dry to moist montane to alpine habitats, often on rocky, sandy to silty soil, at 1000-3550 m. It grows from western Montana and Wyoming south to Arizona and New Mexico.

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

Source FNA vol. 24. FNA vol. 24, p. 717.
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. sesquiflora, C. stricta, C. tacomensis, C. tweedyi, C. ×acutiflora
Name authority Buckley M.E. Jones
Web links