Calamagrostis tacomensis
Calamagrostis deschampsioides
Rainier reedgrass, Tacoma reedgrass
calamagrostide fausse-deschampsie, circumpolar reedgrass
(20)30-55(95) cm, unbranched, smooth or slightly scabrous beneath the panicles;
nodes (1)2(5).
(10)15-45(60) cm, unbranched, smooth beneath the panicles;
nodes 1-2.
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 smooth;
ligules (0.5)1-2.5(3) mm, truncate to obtuse, usually entire, sometimes lacerate;
blades (2)3-8(15) cm long, (1)1.5-2.5(3) mm wide, flat or somewhat involute, abaxial surfaces smooth, adaxial surfaces smooth or slightly scabrous, glabrous or sparsely hairy.
(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.
3-10(12) cm long, 1-4.5 cm wide, pyramidal, open, erect, green to dark purple: branches (2)2.5-4(5.5) cm, spreading, smooth or sparsely scabrous, spikelets usually confined to the distal 1/2.
(4)6-6.5(7) mm;
rachilla prolongations 1.5-2(2.5) mm, hairs (1.5)2(3) mm.
4-5.5(7) mm;
rachilla prolongations 1-2 mm, hairs (0.5)1-1.5 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.
rounded, usually smooth, sometimes scabrous along the midvein, lateral veins mostly obscure, apices acute to acuminate;
callus hairs 2-3 mm, 0.4-0.7 times as long as the lemmas, abundant;
lemmas 3.5^1.5(5.5) mm, 0.5-1(1.5) mm shorter than the glumes;
awns 3-4.5(5.5) mm, attached to the lower 1/3-1/2 of the lemmas, usually exserted, rarely included within the glumes, slender but distinguishable from the callus hairs, weakly to strongly bent;
anthers (1.5)2-2.5 mm.
= unknown.
= 28.
Calamagrostis tacomensis
Calamagrostis deschampsioides
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 deschampsioides is a halophyte that grows, in the Flora region, on coastal dunes and beach ridges, gravel beaches, and in brackish coastal marshes, sometimes with Carex lyngbyei, at or near sea level. Its distribution is circumboreal, extending in North America from the islands of the Bering Sea and coastal Alaska, including the panhandle as far south as 56° N latitude, across the arctic coast to Hudson Bay and northern Labrador. It also extends from the arctic coast of Europe to Siberia and Japan. The alpine habitat reported for the Japanese plants suggests that they might belong to a different taxon.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
OR
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
