THE GRASS FAMILY 



11 



Fig. 4. A floret at flow- 

 ering time. 



of a mass of starchy endosperm. [Endosperm means 

 within the sperm or seed. It is the store of food 

 used by the infant plantlet when 

 it begins to grow.] The "germ" of 

 a kernel of corn is the embryo, 

 while the remainder of the kernel 

 is starchy endosperm. The grain 

 lies in the palea with the hilum 

 (the scar of the point of attach- 

 ment) toward it, and the embryo 

 on the side toward the lemma. 

 Fig. 5 gives two views of a grain, 

 one showing the hilum, the other 

 the embryo. In Fig. 81, A (page 91), .are two ker- 

 nels of corn showing the embryos. The grain with 

 very few exceptions is permanently in- 

 closed in the lemma and palea, the ma- 

 ture floret being the fruit, that is, the 

 seed with its permanent envelopes. The 

 florets are borne in two ranks and alter- 

 nate upon an axis (the rachilla). Below 

 them are two bracts without flowers 

 (the glumes). The glumes, rachilla, and 

 florets together form the spikelet. 



Fig. 6 is a diagram of a branch with 

 Two leaves and flowers arranged as are the 

 glumes, lemmas, paleas, and flowers of 

 a grass spikelet. Fig. 7 is a diagram 

 of a spikelet for comparison with Fig. 6. [The hy- 

 pothetical flower-bearing branchlet is never elongate, 



Fig. 5. 



views 

 grain. 



of 



