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



3b 



Figuke 423. — Calamagrostis bolanderi. Panicle, X 1 ; glumes and floret, X 10. (Bolander, Calif.) 



Callus hairs in 2 tufts, at sides of lemma. 



Plants with creeping rhizomes; spikelets 4 to 5.5 mm. long. 



Blades thin, glabrous on the upper surface, scaberulous beneath; panicle 

 pale, rather loose; glumes relatively thin, 5 to 5.5 mm. long, sca- 

 berulous on the keel toward the summit 12. C. insperata. 



Blades firm, scabrous; panicle tawny to purplish, rather dense; glumes 

 firm, 4 to 4.5 mm. long, scabrous throughout — 13. C. lacustris. 



Plants tufted; spikelets 3.5 to 4 mm. long 14. C. fernaldii. 



Callus hairs surrounding base of lemma 15. C. nubila. 



Awn straight (somewhat bent in C. epigeios and C. lactea), included; callus hairs usu- 

 ally not much shorter than the lemma. 

 Sheaths pubescent on the collar (see C. inexpansa var. barbulata). 20. C. scribxeri. 

 Sheaths glabrous on the collar. 

 Panicle rather loose and open. 



Callus hairs copious, about as long as the lemma; awn delicate, straight. 



21. C. CANADENSIS. 



Callus hairs rather scant, about half as long as the lemma; awn stronger, weakly 



geniculate 22. C. lactea. 



Panicle more or less contracted. 

 Blades flat, rather lax. 



Awn attached near the base; rachilla not prolonged 29. C. epigeios. 



Awn attached at or about middle; rachilla prolonged. 



Glumes scabrous; plant green 23. C. cinnoides. 



Glumes nearly smooth; plant pale 24. C. scopulorum. 



