17 



84. Side nerves of the valve excurrent into bristles ... 



Triraphis. 

 Side nerves of the valve not excurrent into bristles... 85 



85. Branches of panicle very rigid and spreading. SpikeleLs 



distant by more than their own length 



Crossotropis grandiglumis. 

 Spikelets not distant by more than their own length... 86 



86. ^'alves 2 toothed. Awn from the back. (See also 88) ... 



Diplachne. 



Valves minutely 4 toothed. Awn terminal 



Leptocarydium vulpiastrum. 



87. Side nerves of the valve submarginal. Florets usually 



numerous and far exserted from the glumes ... 88 



Side nerves of the valve delicate and not submarginal. 



Florets 2 or 3 with uppermost reduced. Shorter than 



or not much longer than the glumes 89 



88. Valve entire Eragrostis. 



Valve minutely notched, or with 2 lateral teeth. Diplachne. 



89. Keel of glume with pectinate teeth. (See also 24) ... 



Pnonanthium. 

 Keel of glume not with pectinate teeth 90 



90. Glumes unequal. Florets 2-3. (See also 109) ... 



Koeleria cristata. 

 Glumes sub-equal. Florets 2. (See also 112, 114) ... 



Achneria. 



91. Panicle small, falling as a whole together with the sub- 



tending sheath Urochlaena pusilla. 



Inflorescence not deciduous as a whole 92 



92. Spikelets deciduous as a whole, with the glumes ... 93 

 Spikelets breaking up, leaving glumes persistent ... 95 



93. Glumes 5-9 nerved Chaetobromus. 



Glumes 1-3 nerved 94 



94. Lower glume 1 nerved, upper 3 nerved. (See also 83) ... 



Holcus. 

 Both glumes 1 nerved Fingerhuthia. 



95. Valves awned from the back near the middle (sometimes 



awnless in Aira) 96 



Valves awnless or awned. Awns if present terminal, or 

 subterminal, below the tip, or from a sinus 98 



96. Spikelets large or very large. Glumes rounded on the 



back 7-U nerved Avena. 



Spikelets medium sized to small. Glumes more or less 

 keeled. 1-3 rarely — 7 nerved 97 



