156 A TEXT-BOOK OF GRASSES 



D. Spikelets falling off singly or in groups 

 from a continuous rachis; the first 

 glume usually larger than the second. 



Tribe 3. Nazie^e 

 DD. Spikelets falling off singly from the (Par. 212). 



ultimate branches of a panicle; first 

 glume smaller than the second. 



Tribe 4. Melinide^ 

 cc. Lemmas thicker than the glumes, hard- (Par. 213). 



ened Tribe 5. Panice^ 



AA. Spikelets laterally compressed; hilum hnear* (Chap. 17). 



Tribe 6. Oeyze^ 



(Chap. 18). 



Series II 



A. Culms woody Tribe 13. Bambuse^ 



AA. Culms herbaceous. (Par. 270). 



B. Spikelets in spikes or spike-like racemes, 

 c. Spikelets crowded on one side of the 



rachis : • • • : Tribe 10. Chlorides 



cc. Spikelets on opposite sides of the rachis. (Chap. 22). 



Tribe 12. Horded 

 BB. Spikelets in contracted or open panicles. (Chap. 24). 



c. Spikelets with 1 perfect floret. 



D. Perfect floret with 2 sterile lemmas 



below Tribe 7. Phalaride^ 



DD. Perfect floret sohtary, no sterile lemmas (Chap. 19). 



below. Tribe 8. Agrostide^ 



cc. Spikelets with 2 or more florets. (Chap. 20) . 



D. Lemmas awned from the back; glumes 

 usually longer than the first lemma. 



Tribe 9. Avene^ 

 DD. Lemmas awned from the tip or awn- (Chap. 21). 



less Tribe 11. Festuce^ 



(Chap. 23). 



THE MORE IMPORTANT GENERA OF GRASSES 



197. Hackel recognizes over 300 genera of grasses, 

 and some writers, including the author, recognize many 

 more, probably 400 in all. Only a few of the more im- 

 portant genera are described in the present work, the 

 selection being based upon the size of the genus, or the 



* In Gray's "Manual" this tribe is placed in Series II (Gray, Man. ed. 7, p. 88. 

 1908). 



