KEY. 331 



633. Upper pale with the margins pectinately ciliate by 

 stiff, distant hairs (and usually 2-toothed at the apex) . . . 624 



Upper pale more or less evidently ciliate on the 

 nerves, or appai-ently naked 626 



634. Lower pale awned just from below the 2-cleft, or 

 sharply 2-toothed apex 625 



Lower pale awned at the very tip of the 2-toothed, 

 or entire apex, 3-nerved. Stamens 2 or 3. The 1 -sided 

 spikes racemed. Xieptochloa. 



Gr. III. 23. 



W. V. 53. 



635. Lower pale either convex on the back, or compress- 

 ed-keeled, 5- to 9-nerved. Style or stigmas proceeding from 

 below the tip of the ovary, on its anterior face. Stamens 3. 

 Panicle simple or compound. Bromus. 



Gr. IV. 37. 

 W. IIL 30. 



Lower pale rounded on the back, about ^rnerved, 

 much longer than the upper one. Styles from the tip of the 

 ovary. A short-bearded tuft at the base of gach flower. 



Avena striata, Mx. 

 {Trisetum purpurascens, Torr.) 

 Gr. VI. 50. 

 W. 29. 



636. Flowers rounded on the back 62T 



Flowers compressed-keeled on the back 634 



637. Flowers all -equally developed, or nearly so. . . . 628 

 Spikelets oblong, or ovate-oblong, awnless, with 3 



to 5 flowers, and only the 2 lower of them developed and 

 fertile, the rest imperfect, dissimilar, convolute around each 

 other. Lower glume almost equalling the spikelet. Lower 

 pale minutely scabrous on the nerves, blunt at the summit. 

 Panicle simple and sparingly branched. 



Melica mutica, Walt. 



Gr. IV. 30. 



W. in. 38. 



638. Glumes both, or one of them shorter thar the low- 

 est flowers, or, if longer, at least shorter than the spikelet. 



629 



