i56 



1 Spikelets small (2| lines to less than 1 line). 

 Valve of the upper floret 2-setose, minutely 

 2-tootlied or entire, awn sometimes reduced or 

 absent. Flaps of the pale auricled. 



1 Spikelets large (2 line to 1| inch). Valve of the 

 upper floret always distinctly 2-toothed or 

 2-lobed, awn always laieed. Flax)s of the pale 

 not auricled. 



Spikelets as in Trichopteryx. 



Arukdinella. 



Trichopteryx. 

 Tristachya. 



TRIBE IV. AVENE^. 



awn if present, from the 



Valves awnless or awned 



back of the valve. 1 



Valves awned, rarely mucronate, awn or mucro from 

 the sinus or the more or less distinctly 2-lobed 

 valve, lobes often bristle-like. 2 



1 Florets 3, heteromorphous ; the lower 2 male or 

 barren, awned, the terminal hermaphrodite, 

 awnless. Rhachilla not continued beyond the 

 upper floret. Anthoxanthdm. 



1 Florets 2 or more, the uppermost gradually re- 

 duced. Rhachilla glabrous or almost so. Valves 

 3-5 nerved, awnless or mucronate or minutely 

 awned from, or from below the tip. Panicle 

 spiciform. K(eleria. 



1 Spikelets erect or suberect. Florets 2 or more, 

 the uppermost gradually reduced. Glumes 

 usually 1-3 nerved. Valves herbaceous, 5-9- 

 nerved, rather firm, awned from the back. 

 Ovary top hairy. Perennial. Avenastrdm. 



2 Florets 2, continuation of rhachis minute or bristle- 

 like. Lobes of the valve 2-rarely 4-fid, both or 

 all 4 divisions bristle-like, or only the inner, 

 with the outer lobule minute and more or less 

 adnate to it. Pentaschistis. 



TRIBE V. ARUNDINE^. 



Florets heteromorphous ; the lowest male or barren, 

 the rest hermaphrodite, hairy from the long 

 slender callus, otherwise glabrous. 



Phraomites. 



FLORET I. 



TRIBE VI, AGROSTE^. 



Glumes aw^ned, usually from a minute notch or sinus. Polypogon. 



Glumes not awned. Callus glabrous or shortly bearded. Agrostih. 

 Glumes not awned. Callus with long fine hairs, 



several times longer than the valve, CALAMAOBOBTifi, 



