MANUAL OF THE GRASSES OF THE UNITED STATES 



315 



Figure 628.— Distribution of 

 Calamagrostis pickeringii. 



lax, 10 to 15 cm long (rarely longer) ; glumes about 4 mm long, acumi- 

 nate; lemma a little shorter than the glumes, sharply toothed, the awn 

 about as long as the glumes or a little longer, feebly bent, the callus 

 hairs about half as long as the lemma; rachilla minute, its hairs nearly 

 as long as the lemma. % — Moist meadows, Montana and Wash- 

 ington to Colorado and Oregon; infrequent (fig. 630). 



16. Calamagrostis canadensis (Michx.) Beau v . Bltjejoint. (Fig. 

 631, A.) Culms suberect, tufted, 60 to 150 cm 

 tall, with numerous creeping rhizomes ; sheaths 

 glabrous or rarely obscurely pubescent; blades 

 numerous, elongate, flat, rather lax, scabrous, 4 

 to 8 mm wide; panicle nodding, from narrow 

 and rather dense to loose and relatively open, 

 especially at base, 10 to 25 cm long; glumes 

 usually 3 to 4 mm long, smooth or more com- 

 monly scabrous, acute to acuminate; lemma 

 nearly as long as glumes, smooth, thin in texture, the awn delicate, 

 straight, attached just below the middle and extending to or slightly 

 beyond its tip, the callus hairs abundant, about as long as lemma; 

 rachilla delicate, sparsely long-pilose. % — Marshes, wet places, 



open woods, and meadows, Green- 

 land to Alaska, south to Maryland, 

 North Carolina (Roan Mountain), 

 Missouri, Kansas, Colorado, Ari- 

 zona, and California (fig. 632). 

 A widely distributed and exceed- 

 ingly variable species. Characters 

 used to differentiate the many 

 proposed varieties are not corre- 

 lated in the larger proportion of 

 specimens. The panicle varies in 

 density and the glumes in size 

 and scabridity. The following 

 varieties are recognizable but are 

 connected with the species by 

 many intergrading specimens. 

 Calamagrostis canadensis var. scabra (Presl) Hitchc. (Fig. 

 631, B.) Differing in having spikelets 4.5 to 6 mm long, the glumes 

 rather firm, hispidly short-eiliate on the keel, strongly scabrous other 



Figure 629.- 

 glumes and 



-Calamagrostis scribneri. Panicle, 

 floret, X 10. (Rydberg 3083, Mont.) 



21 



Mountains of 



wise, but the greater scabridity not constant. 

 New England, New York, and northward, and 

 along the Pacific coast from Washington to 

 Alaska. This form has been referred to C. langs- 

 dorjii (Link) Trim, which proves to be an Old 

 World species not found in America. 



Calamagrostis canadensis var. macouni- 

 ana (Vasey) Stebbins. (Fig. 631, C.) Differing 

 from C. canadensis in the smaller spikelets, 

 about2mmlong. Scarcely a distinct variety. 91 

 — Saskatchewan (Macoun44, 45), Minnesota (Bemidge), South Dakota 

 (Chamberlin, Redfield), Iowa, Nebraska (Central City), Missouri 

 (Lake City, Little Blue), Montana (Manhattan), Yellowstone Park, 

 Washington (Spokane County), Oregon (Crook County). 



Figure 630.— Distribution of 

 Cala magroslis scribneri. 



