110 Key to the System of 



540. Spikelets with five awns. 



Spikelets rather large, in a panicle ; fruit-supporting bract 

 terminated by one long and four small or minute awns ; 

 stamens three. Fentapogon. 2060 



Spikelets with three awns ... ... 541 



541. Covering bract longer than the fruit-supporting bract. 



Spikelets quite large, in a panicle ; fruit-supporting bract 

 terminated by three awns, the middle one much elongated 

 and twisted ; stamens three. Aiiisopogon. 2061 



Covering bract shorter than the fruit-supporting bract. 



Spikelets generally rather large, in a spreading or con- 

 tracted or sometimes raceme-like panicle ; fruit-support- 

 ing bract terminated by three disunited or downward 

 connate awns ; stamens three. Aristida. 2062 



542. Spikelets long-awned. 



Panicle spreading or contracted ; flowers usually rather 

 large ; awn terminal, valid ; stamens generally three. 



(Dichelachne.) Stipa. 2066 



Spikelets short-awned or awnless ... ... ... 543 



543. Fruit-supporting bract terminated by three minute 



awns. 



Panicle generally spike-like ; covering bract minutely two- 



awned ; stamens three. Amphipogon. 2076 



Fruit-supporting bract terminated by one small awn 

 or awnless ... ... ... ... ... ... 544 



544. Awn terminal. 



Panicle contracted into an headlet or a cluster ; flowers 

 small ; awn from between the two minute pointed lobes 

 of the fruit-supporting bract, very slender. 



Echiiiopogon. 2077 



Awn dorsal or absent. 



Panicle spreading or contracted, not rarely spike-like; 



flowers always small ; awn very slender. Agrostis. 2078 



