4 ELEMENTS OF STRUCTURAL BOTANY. 



piant the bristles are in clusters and are barbed upwards. 

 The spikes are tawny-yellow in colour. 



113. These examples, if conscientiously studied with 

 the aid of the plants themselves, will give you a good 

 general idea of the kinds of variation which may be looked 

 for in the Grasses. They may be said, roughly, to consist 

 in the presence or absence of glumes, of awns, and of the 

 upper palet ; in the general aspect of the whole flower- 

 cluster ; in the number of flowers in the spikelets ; and 

 in the varying relative size of the glumes and of the palets. 



114. The Order as a whole is distinguished by the 

 following characters : 



1. The sheaths of the leaves are split on the side of the 



culm opposite the blade. 



2. The separate flowers are enclosed in glumaceous bracts 



called palets 



3. The perianth is represented by the lodicules. 



4. The stamens are three in number, and the pistil is 



syncarpous (two carpels), with a one-celled ovary 

 producing a single seed, which is always albuminous 

 with the embryo on one side. 



CHAPTER XV 



COMMON CHARACTERISTICS OP THE PLANTS JUST EXAMINED 



STRUCTURE OF THE SEED IN MONOCOTYLEDONS. 



4 15. It is now to be pointed out that the plants 

 examined in the last three chapters, though differing in 

 various particulars, yet have some characters common to 

 all of them, just as the group ending with Maple was 



