Calamagrostis koelerioides
Calamagrostis tweedyi
dense-pine reed grass, fire reedgrass
Cascade reedgrass, Tweedy's reedgrass
(26)60-85(120) cm, unbranched, slightly scabrous;
nodes 2-3(5).
(47)60-120(150) cm, unbranched, smooth, rarely slightly scabrous;
nodes 2-3.
and collars usually scabrous, rarely smooth, glabrous;
ligules (1.5) 2-4.5(7) mm, truncate to obtuse, entire or sometimes lacerate;
blades (2)9-20(30) cm long, (2)2.5-4.5(8) mm wide, flat, slightly scabrous, adaxial surfaces glabrous or sparsely hairy.
and collars smooth;
ligules (1)3.5-6(8) mm, obtuse, lacerate;
blades (3)4-20(38) cm long, (2)3-8(13) mm wide, culm blades wider than 6 mm, flat, abaxial surfaces smooth, adaxial surfaces smooth or slightly scabrous, glabrous or sparsely hairy.
(4)10-13(16) cm long, about 1 cm wide, contracted, erect to slightly nodding, often slightly interrupted towards the base, straw-colored or pale green to pale purple;
branches (1.1)2.8-4(6) cm, scabrous, spikelet-bearing to the base.
7-16(19) cm long, (1)1.5-2 cm wide, erect, usually contracted, sometimes interrupted near the base, pale purple to purple;
branches (0.2)2.4-6.7(7.7) cm, smooth, sometimes sparsely scabrous distally, spikelet-bearing to the base.
(4)4.5-6(7) mm;
rachilla prolongations 1.5-2.5(3) mm, hairs 1.5-2 mm.
(4.5)5.5-8(9) mm;
rachilla prolongations (0.5)1-2(4) mm, hairs 1.5-3 mm.
slightly keeled, keels smooth or slightly scabrous distally, lateral veins visible but not prominent, apices acute;
callus hairs 1.5-2 mm, 0.3-0.4 times as long as the lemmas, sparse;
lemmas (3.5)4-5(6) mm, 0.5-1.5 mm shorter than the glumes;
awns 4-5.5 mm, attached to the lower 1/10 – 1/5 of the lemmas, exserted, sometimes barely so, stout, distinguishable from the callus hairs, bent;
anthers 2-3.5 mm.
keeled, smooth or the keels scabrous, lateral veins prominent, apices acute;
callus hairs 0.8-1 mm, 0.2-0.3 times as long as the lemmas, sparse;
lemmas (4)4.5-6.5(7.5) mm, 0-1.5 mm shorter than the glumes, scabridulous;
awns 6-8 mm, attached to the lower 1/5 – 3/10 of the lemmas, exserted more than 2 mm, stout, easily distinguished from the callus hairs, bent;
anthers 2-3.5 mm.
= 28.
= unknown.
Calamagrostis koelerioides
Calamagrostis tweedyi
Calamagrostis koelerioides grows in mountain meadows, chaparral, and Jeffrey pine and blue spruce forests, and on talus slopes, dry hills, and ridges, occasionally on serpentine soils, at 50-2100 m. It extends from Washington south to southern California and east to Montana and western Wyoming.
Calamagrostis koelerioides is similar to C. rubescens (p. 723). The two have traditionally been distinguished by the presence of hairs on the leaf collars in C. rubescens, and their absence in C. koelerioides; a more reliable differentiation is the longer lemmas, glumes, and awns of C. koelerioides compared to C. rubescens.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Calamagrostis tweedyi grows in montane to subalpine moist meadows and coniferous forests, often in association with Carex geyeri, at 900-2000 m. Its range extends from Washington and Oregon to western Montana.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
WA
