CHAPTEE XIII. 

 THE GRAMINEJE. 



EXERCISE LYII. 

 Characters of the Graminece. 



THERE is a large group of plants blossoming in 

 peculiar-looking spikes, heads, and panicles, the flow- 

 ers of which are furnished with green or brown scales, 

 called glumes, whence the entire group is known as 

 the Glumacese. They constitute a twelfth part of the 

 described species of flowering plants, and at least 

 nine-tenths of the individuals composing the vegeta- 

 tion of the world. They grow everywhere. All 

 grasses and all the cultivated crops of grain belong 

 among them, besides many other plants not so im- 

 portant to man. They have true flowers, but no 

 calyx or corolla. The Glumacese are divided into two 

 groups ; one group the sedges having solid stems, 

 while the other the grasses has hollow stems. The 

 flowers of both these groups have a special structure, 

 which your previous study will not enable you to 

 understand. 



From this large class we will select examples 

 that belong to the family of grasses or Gramineae, 

 the members of which have hollow stems, and the 

 sheaths of their ligulate leaves are spit in front. 



Gather specimens of wheat, if possible, in bios- 



