238 



Figure 316. — Agropyron subsecundum, 

 X 1. (Shear 452, Mont.) 



MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



ly nodding, 6 to 15 cm. long, some- 

 times unilateral from twisting of the 

 spikelets to one side, the rachis sca- 

 brous or scabrous-ciliate on the 

 angles, sometimes disarticulating; 

 spikelets rather closely imbricate, 

 few-flowered, the rachilla villous, the 

 callus of the florets short-pilose; 

 glumes broad, rather prominently 4- 

 to 7-nerved, nearly as long as the 

 spikelet, tapering into an awn; lem- 

 mas obscurely 5-nerved, the nerves 

 becoming prominent toward the tip, 

 the awn straight or nearly so, usually 

 1 to 3 cm. long. % — Moist mead- 

 ows and open woods, Newfoundland 

 to Alaska, south to the mountains 

 of Maryland, west to Washington 

 and California, and south to New 

 Mexico and Arizona. Said by Malte 

 to be self-pollinated. This is the 

 species which has generally been 

 called by American botanists A. 

 caninum (L.) Beauv.; that is a 

 European species, differing in having 

 3-nerved glumes. 



Agropyron subsecundum var. 

 andinum (Scribn. and Smith) Hitchc. 

 Culms mostly not more than 50 cm. 

 tall, loosely tufted, usually geniculate 

 at base; lower sheaths pale, usually 

 papery; spike short; awns mostly 5 

 to 10 mm. long, often curved. An 

 alpine form of mountain meadows. 

 % — Montana to Washington, south 

 to Colorado and Nevada. 



Agropyron caninum (L.) Beauv. 

 Glumes 3-nerved. 2| — Ballast 

 near Portland, Or eg. ; adventive from 

 Europe. 



13. Agropyron trachycaulum (Link) 

 Malte. Slender wheatgrass. (Fig. 

 317.) Resembling A. subsecundum; 

 sheaths glabrous or rarely pubescent; 

 blades mostly 2 to 4 mm. wide; spike 

 usually more slender, 10 to 25 cm. 

 long, sometimes unilateral; spikelets 

 from rather remote to closely imbri- 

 cate; glumes and lemmas awnless or 

 nearly so. % (A. tenerum Vasey, 

 A. pauciflorum (Schwein.) Hitchc.) — 

 Labrador to Alaska, south to the 

 mountains of West Virginia, Missouri, 

 New Mexico, and California; north- 



FiGtrRE317. — Agropyron trachy- 

 caulum, X 1. (Shear 404.) 



minutely toothed apex, coarsely pu- 

 bescent, the scabrous awn 8 to 10 mm. 

 long. % (Elymus vulpinus Rydb.) 

 — Moist ground, Grant County, Nebr. 

 and Livingston, Mont. 



12. Agropyron subsecundum (Link) 

 Hitchc. Bearded wheatgrass. (Fig. 

 316.) Green or glaucous, without 

 creeping rhizomes; culms erect, tuft- 

 ed, 50 to 100 cm. tall; sheaths gla- 

 brous or rarely pubescent; blades flat, 

 3 to 8 mm. wide; spike erect or slight- 



