CHLORIDES. 393 



U. S. Dept. Agricul. 491; Nor. Trans. Surv., Canhy & ScriO- 

 ner; Brandegee 375, 1179; Yellowstone Piirk, Timedij 597, 1070 

 in part. 



Lower Canada to Rocky Mountains, British America to 

 Oregon, California. 



Teibe X.— CHLOEIDE-E. 



Spikelets 1- to several-flowered, sessile or nearly so in two rows on 

 the outer side of a rachis that is neither notched nor articulate. 

 Spikes usually several and often digitate. The inflorescence re- 

 sembles that of Pasixdum; the spikelets those of Festuce*. The 

 awns when present are terminal and straight; palea 3-nerved; 

 grain not adherent, uufurrowed. 



A. One or more perfect flowers in each spikelet (a) 



a. One perfect flower (very rarely two) in each spikelet. . (b) 

 b. No sterile glumes, and only rarely a prolongation 



of the rachilla above the single flower (c) 



c. Spike single, terminal, floral glume shorter than 

 the 1-nerved emjity glumes; perennial. ... 82 



c. Spikes 2-6, digitate; perennial 83 



c. Spikes 3-10, recurved, floral glume longer than 



the 1-nerved empty glumes 89 



c. Spikes 3-30, racemose, straight, spikelets fall- 

 ing from the rachis entire when mature. . . 84 

 b. One or more sterile glumes (very rarely a sterile 



flower) above the perfect flower (d) 



d. Spikes 1-2, terminal, usually curved, pectinate. 85 

 d. Spikes 1-20, digitate, nearly straight, not pecti- 

 nate, floral glume Avith 1 awn or awnless. ... 86 

 d. Spikes 15-30 in approximate whorls or digitate, 



straight, floral glumes with 3 awns 87 



d. Spikes 10-30, remote^ racemose, straight, slen- 

 der, spikelets remote 88 



d. Spikes few to many, racemes remote, straight 

 or curved, often pectinate, spikelets crowded. . 90 



