MANUAL OF THE GRASSES OF THE UNITED STATES 



319 



9. Calamagrostis rubescens Buckl. 

 Pinegrass. (Fig. 431.) Culms slender, 

 tufted, 60 to 100 cm. tall, with creep- 

 ing rhizomes ; sheaths smooth, but pu- 

 bescent on the collar, sometimes ob- 

 scurely so; blades erect, 2 to 4 mm. 

 wide, flat or somewhat involute, sca- 

 brous; panicle narrow, spikelike or 

 somewhat loose or interrupted, pale 

 or purple, 7 to 15 cm. long; glumes 4 

 to 5 mm. long, narrow, acuminate; 

 lemma pale, thin, about as long as 

 glumes, smooth, the nerves obscure, 

 the awn from near base, geniculate, 

 exserted from side of glumes, 1 to 2 

 mm. long above the bend, the callus 

 hairs scant, about one-third as long 

 as the lemma; rachilla 1 mm. long, the 

 sparse hairs extending to 2 mm. 01 

 — Open pine woods, prairies, and 



Figure 431. — Calamagrostis rubescens. Panicle, X 1; 

 glumes and floret, X 10. (Sandberg and Leiberg 

 Wash.) 



Figure 430. — Calamagrostis cainii. Panicle, X 1 ; 

 glumes and floret, X 10. (Underwood 1210, Tenn.) 



Figure 432. — Calamagrostis porteri. Glumes and 

 floret, X 10. (Porter, Pa.) 



banks, British Columbia, south to 

 northern Colorado and central Cali- 

 fornia. A valuable range grass. A large 

 form with dense lobed panicle has 

 been differentiated as C. cusickii 

 Vasey. 



10. Calamagrostis porteri A. Gray. 

 (Fig. 432.) Culms slender, 60 to 120 

 cm. tall, with slender rhizomes; 

 sheaths pubescent on the collar; 

 blades flat, spreading, lax, 4 to 8 mm. 

 wide; panicle narrow but rather loose, 

 erect or somewhat nodding, 10 to 15 



