MANUAL OF THE GRASSES OF THE UNITED STATES 249 



narrow, short; spike very bristly, 2 to 5 cm long (excluding the long 

 spreading awns); glumes subulate, smooth, indurate below, tapering 

 into a slender awn 1 to 2.5 cm long; lemmas lanceolate, 3-nerved, 

 6 mm long, very scabrous, tapering into a flat awn 5 to 10 cm long. 

 O Open ground, Washington to California, infrequent; introduced 

 from Europe. 



2. Elymus mollis Trin. AMERICAN DUNEGRASS. (Fig. 479.) 

 Culms stout, pubescent below the spike, glaucous, 60 to 120 cm tall, 

 with numerous overlapping basal leaves, the rhizomes widely creeping; 

 blades firm, 7 to 12 mm wide, often involute in drying; spike erect, 



FIGURE 478. Elymus caput-medusae, X 1. (Vasey 3076, Wash.) 



dense, thick, soft, pale, 7 to 25 cm long; glumes lanceolate, flat, 

 many-nerved, scabrous or pubescent, 12 to 25 mm long, acuminate, 

 about as long as the spikelet; lemmas scabrous to felty-pubescent, 

 acuminate or mucronate. Ql Sand dunes along the coast, 

 Alaska to Greenland, south to Massachusetts and central California; 

 along Lakes Superior and Michigan (fig. 480) ; also eastern Siberia to 

 Japan. Closely related to the European E. arenarius L. with culm 

 smooth below the spike and glabrous glumes. A form found along 

 the coast of Washington with somewhat compound spikes has been 

 differentiated as E. arenarius var. compositus (Abrom.) St. John, 



