717 



1-3 imperfect ones. 



30 Distlchlis Flowers dioecious: flowering glumes much compressed 

 laterally, many-nerved, somewhat coriaceous. 



****** Glumes 1-3-nerved. 



40 Catabrosa Glumes membranous, erose-truncate. 



41 tiraphephornm Rachella hirsute with stiff hairs, extended into a 

 hairy appendage : flowering glumes membranous.' 1 



42 Panicularia Spikelets several-flowered ' decidiibus, the rachella 

 breaking up into joints : flowering glumes rounded on the back, the 

 5-7 nerves not reaching the scarious mostly obtuse apex. 



43 Pnccinellia Flowering glumes chartaceous., convex on the back, 

 faintly 2-nerved, the nerves not reaching the obtuse subdenticulate or 

 or mueronulate apex. 



44 Pleuropogon Flowering glumes chartaceous, several-nerved, the 

 nerves not reaching the truncate awned apex. 



45 Poa Flowering glumes laterally compressed, mostly keelekl, 5-nerved, 

 membranous, the margins or nerves below with cobweby hairs or pu- 

 bescent: palet falling with the glume. 



46 Eragrostis Flowering glume 3-nerved, keeled, deciduous, leaving 

 the persistent palet. 



* *. * Spikelets several-flowered : lowest flowers all perfect : grain 

 adherent to the palet. 



47 BRIZA Spikelets somewhat heart-shaped : flowering glumes rounded, 

 many-nerved, becoming ventricose. 



48 Festuca Spikelets flattish : flowering glumes rounded on the back, 

 few-nerved, pointed or awned at the tip: ovary mostly smooth. 



49 Bromus Spikelets flattened : flowering glumes convex to compressed, 

 mostly awned below the tip : ovary pubescent. 



TRIBE vm HORDEAE Spikelets one- to several-flowered, ses- 

 sile in alternate notches on the opposite sides J of a zigzag rachis, 

 either solitary or several together. 



* Spikelets single at each joint of the rachis. 



50 Scribneria Spikes slender, solitary : spikelets 1-fiowered, almost em- 

 bedded in the notches of the rachis. 



51 LOLIUM Spikelets several-flowered, placed with the edge next to the 

 rachis : the inner glumes wanting except the terminal one. 



62 Agropyfon Hpikelets 3- to several-flowered, placed flatwise on the 

 rachis : both glumes present, standing right arid left. 



* * Spikelets 2 or more at each joint of the rachis : glumes anterior, 

 forming a sort of involucre to the spikelet. 



58 Hordenm Spikelets 1- to several-flowered, in 'three's at each joint: 

 lateral spikelets usually sterile. , 



64 Elymus Spikelets 1- to several-flowered, 2-4 at each joint, all perfect 

 and similar : glumes shorter than the spikelets: flowering glumes not 

 long-awned. 



55 Sitanion Spikelets 1- to SPveral-flowered, 2-4at*ach joint, all perfect : 

 glumes very long, usually 2-parted to the base and long-awned : flow- 

 ering glumes long-awned and 2- toothed, or 3-awnexL 



