MANUAL OF THE GRASSES OF THE UNITED STATES 



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, 

 Idaho and Washington to California; 

 a bad weed, spreading on the ranges 

 in northern California; introduced 

 from Europe. 



2. Elymus mollis Trin. American 

 dunegrass. (Fig. 333.) Culms stout, 

 pubescent below the spike, glaucous, 

 60 to 120 cm. tall, with numerous 

 overlapping basal leaves, the rhi- 

 zomes widely creeping; blades firm, 

 7 to 12 mm. wide, often involute in 

 drying; spike erect, dense, thick, soft, 

 pale, 7 to 25 cm. long; glumes lan- 

 ceolate, 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. 

 % — Sand dunes along the coast, 

 Alaska to Greenland, south to Long 

 Island, N.Y., and central California; 

 along Lakes Superior and Michigan; 

 also eastern Siberia to Japan. Closely 

 related to the European E. arenarius 



251 



Figure 333.- 



-Elymus mollis, X 1. (Henderson 2169, 



Wash.) 



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, but the 

 plants are found to be diseased. 



3. Elymus vancouverensis Vasey. 

 (Fig. 334.) Resembling E. mollis, less 

 leafy; spike somewhat interrupted, 

 purplish ; glumes narrowly lanceolate, 

 firm, gradually acuminate, 1 to 1.5 



Figure 334. — Elymus vancouverensis, X 1. (Piper 812, Wash.) 



