MANUAL OF THE GKASSES OF THE UNITED STATES 317 



17. Calamagrostis lactea Beal. (Fig. 633.) Culms ascending, 80 

 to 150 cm tall, weak, the nodes subgeniculate, 

 with a short knotty rhizome; sheaths scaber- 

 ulous; ligule rather firm, 3 to 5 mm long; 

 blades elongate, flat, lax, scabrous, 6 to 12 

 mm wide; panicle pale, narrowly pyramidal, 

 12 to 20 cm long, loosely flowered; glumes 5 

 to 6 mm long, scabrous, acuminate; lemma 



cVinrtor tVian fVia crlnmaa crnKrrm<i tViA onAY FIGURE 632. Distribution of 



snorter tnan tne gmmes, scaorous, me apex caiamagrostis canadensis. 



setaceous-toothed, the awn attached near the 



base, about equaling the lemma, weakly geniculate; palea slightly 



FIGURE 633. Calamagrostis lactea. Panicle, X 1; glumes and floret, X 10. (Dupl. type.) 



exceeding the lemma, the callus hairs about half as long; rachilla 



minute, sparsely pi- 

 lose. 01 Mountain 

 slopes, Washington 

 and Oregon, appar- 

 ently rare. 



18. Calamagrostis 

 cinnoides (Muhl.) 

 Barton. (Fig. 634.) 

 Glaucous; culms 

 rather stout, erect, 80 

 to 150 cm tall, with 

 slender rhizomes read- 

 ily broken off; sheaths 

 and blades very sca- 

 brous, sometimes 

 sparsely hirsute, the 

 blades flat, 5 to 10 mm 

 wide; panicle erect, 

 dense, more or less 

 lobed (somewhat open 

 at an thesis), 8 to 20 cm 



long, purple-tinged; glumes 6 to 7 mm long, scabrous, long-acuminate 



FIGURE 634. Calamagrostis cinnoides. Panicle, X 1; glumes and 

 floret, X 10. (Chase 7518, Md.) 



