Calamagrostis tacomensis
Calamagrostis ophitidis
Rainier reedgrass, Tacoma reedgrass
serpentine reed grass
(20)30-55(95) cm, unbranched, smooth or slightly scabrous beneath the panicles;
nodes (1)2(5).
(30) 55-80(100) cm, unbranched, scabrous beneath the panicles;
nodes (1)2(5).
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.
and collars usually scabrous, rarely smooth;
ligules (0.5)2-5.5(7) mm, usually truncate, entire to slightly lacerate;
blades (8)10-20(27) cm long, (1.5)2-3(4) mm wide, usually involute, abaxial surfaces usually scabrous, rarely smooth, adaxial surfaces scabrous, glabrous or sparsely hairy, both surfaces with abundant white glands between the veins, visible only with magnification.
(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.
(6)8-11(15) cm long, (1)1.2-1.5 cm wide, contracted, mostly erect, pale green to green;
branches 2-4(4.5) cm, scabridulous, usually spikelet-bearing to the base.
(4)6-6.5(7) mm;
rachilla prolongations 1.5-2(2.5) mm, hairs (1.5)2(3) mm.
(4.5)5-7(8) mm;
rachilla prolongations about 1.5 mm, hairs 1-2 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.
keeled, usually scabrous over the entire surface, rarely only the keels scabrous distally, lateral veins prominent, apices acute to acuminate;
callus hairs 1-1.5(2) mm, 0.2-0.4 times as long as the lemmas, sparse;
lemmas 4.5-6.5 mm, 0-2 mm shorter than the glumes;
awns 5-6(8) mm, attached to the lower 1/10 – 1/5 of the lemmas, exserted less than 2 mm, stout, distinguishable from the callus hairs, bent;
anthers (2.5)3-3.5(4) mm.
= unknown.
= 28.
Calamagrostis tacomensis
Calamagrostis ophitidis
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.)
Calamagrostis ophitidis grows in meadows, seeps, grasslands, and chaparral, as well as in coniferous forests, on serpentine outcrops and soils, at 50-1100 m. It is known only from Sonoma, Marin, Mendocino, Lake, and Napa counties in California.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
OR
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
CA
