CLASSIFICATION 43 



CHAPTER V 



CLASSIFICATION. 



The family Gramineae is usually divided into two series taking 

 into consideration the presence or absence of a joint in the pedicel 

 or rachis, the number of flowers in the spikelet and the posi- 

 tion of the fertile flower. All the species in which there is a joint 

 just below the spikelet, in the pedicel, in the rachis, or at the base 

 of a cluster of spikelets come under one series PanicaceaB. The 

 spikelets of the grasses coming under this series, when mature, fall 

 away singly by themselves, or with their pedicels, or in groups 

 with portions of the rachis. The spikelets are all similar and 

 consist of usually four glumes. Each spikelet contains a single 

 perfect flower and sometimes in addition a staminate flower just 

 below the perfect flower. In this series the tendency for imperfec- 

 tion is always confined to the lower flowers, the terminal flower 

 alone being perfect. For inclusion under this series the grass 

 plant should have both the characters, articulation and position of 

 the flower as mentioned above. 



The second series Poaceae includes those grasses in which the 

 spikelets are one to many-flowered and continuous with their 

 pedicels. But the rachilla of the spikelet may be jointed just 

 above the empty glumes or between the flowering glumes. The 

 complete flower is the lowest and the tendency for imperfection is 

 in the upper flowers. 



Of the two series the Panicaceae appears to be more highly 

 developed than the Poaceae. 



KEY TO TRIBES. 



Scries I. Panicaceaz. 



A. Rachis of inflorescence not jointed. 



Spikelets 2-flowered ; upper flower 



bi-sexual and lower male or neuter ; 



the first glume the smallest ••• I. Panicese. 



Spikelets i-flowered ; 



Spikelets articulate on their 

 pedicels and falling away from 

 them ; flowers bi-sexual and 

 usually with six stamens ... II. Oryzeas. 



Spikelets falling away with their 

 pedicels; flowers bi-sexual or 

 rarely imperfect... ... ... III. Zoysieai. 



