Calamagrostis canadensis
Calamagrostis scopulorum
bluejoint, bluejoint grass, bluejoint reedgrass, calamagrostide du Canada, Canada reed grass
ditch reedgrass, Jones' reedgrass
(32)65-112(180) cm, often branching above the base, smooth or slightly scabrous beneath the panicles;
nodes (2)3-7(8).
(40)50-92 cm, sometimes branched, sparsely to densely scabrous;
nodes 2-3.
smooth or scabrous;
collars usually scabrous, rarely smooth or hairy;
ligules (1)3-8(12) mm, lacerate;
blades (10)16-31(50) cm long, 2-8(11) mm wide, flat, lax, abaxial surfaces scabrous, adaxial surfaces usually strongly scabrous, rarely smooth or with scattered hairs, often glaucous.
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.
(6)9-17(25) cm long, (1)2-4(8) cm wide, often contracted when young, open at maturity, nodding, usually purplish, sometimes greenish to straw-colored;
branches 2.7-6(12) cm, scabrous, spikelets sparsely to densely concentrated on the distal 2/3.
(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.
2-4.5(5.2) mm;
rachilla prolongations 0.5-1 mm, hairs 1.5-3.2 mm.
(4)4.5-6 mm;
rachilla prolongations 1-2 mm, hairy throughout, hairs 1.5-2.5 mm.
rounded or keeled, smooth or scabrous, keels often long-scabrous, lateral veins obscure to prominent, apices acute to acuminate;
callus hairs (1.5)2-3.5(4.5) mm, (0.5)0.9-1.2(1.5) times as long as the lemmas, abundant;
lemmas 2-3.1(4) mm, 0-2.1 mm shorter than the glumes;
awns 0.9-3.1 mm, attached to the lower (1/10)1/5-1/2(7/10) of the lemmas, usually not exserted, delicate, often difficult to distinguish from the callus hairs, usually straight;
anthers (0.8)1.2-1.6(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.
= 42-66.
= 28.
Calamagrostis canadensis
Calamagrostis scopulorum
Calamagrostis canadensis is a species of moist meadows, thickets, bog edges, and forest openings. It grows from sea level to 3400 m. It occurs widely throughout the Flora region, except in Oklahoma, Texas, and the southeastern United States. Its range also extends from northern Asia to northeastern China and Japan, with additional scattered populations elsewhere in Asia. Calamagrostis canadensis is closely related to, and possibly conspecific with, the European C. purpurea (Trin.) Trin. It hybridizes with Ammophila breviligulata (p. 777) in Grand Island, Michigan and on the adjacent mainland, forming xCalammophila don-hensonii Reznicek & Judz. Calamagrostis canadensis also appears to form hybrids with the nearly sympatric C. porteri (p. 721) in rocky wooded sites in central Virginia. These putative hybrids have hairy collars, relatively long callus hairs, and short awns. The apparently sterile C. perplexa (see previous) is intermediate between C. canadensis and C. porteri (Greene 1980).
A high degree of pollen sterility has been documented in some populations, suggesting that seed formation via apomixis is common; sexual reproduction is also documented. The many forms, varieties, and subspecies that have been described for this species probably represent clones. The three varieties recognized here intergrade, and an argument could be made that their recognition is not warranted. Nevertheless, the extreme forms along the gradient of variation can be distinguished most readily by the glumes.
(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.)
1. Spikelets (3.5)4-4.5(5.2) mm long; glumes usually scabrous over the entire surface, the prickles on the keels hairlike, often bent; glume apices distinctly acuminate | var. langsdorffii |
1. Spikelets 2-4 mm long; glumes smooth or scabrous, often scabrous only on the keels, prickles straight; glume apices acute, rarely acuminate. | → 2 |
2. Spikelets 2.5-4 mm long, lemmas usually shorter than the glumes; glumes rounded to broadly keeled, with raised midveins; glume apices usually acute, rarely acuminate | var. canadensis |
2. Spikelets 2-3 mm long; lemmas usually about as long as the glumes; glumes rounded, midveins not raised; glume apices acute | var. macouniana |
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