INFLORESCENCE AND FLOWER 17 



and so they arc inseparable. Such a fruit is termed a caryopsis or 

 grain. Though in the vast majority of grasses the pericarp is 

 inseparable, in a few cases it is free from the seed-coat as in 

 Sporobolus indicus and Eleusine indica. 



FL 

 G / 



1 i|ii : M 



i|§ J:- ■ 



■ VAr, 



Fig. 20. — Longitudinal section of a portion of the grain of An<lropogon Sorghum, x 2S0 



P. Pericarp; Sc. seed-coat ; A aleurone layer; E. endosperm. S. scutellum; Rs. 

 root-sheath ; Re. root-cap ; R. radicle ; P!. plumule ; G. growing point. 



The caryopsis consists of an embryo on one side at the base 

 and the endosperm occupies the remaining portion. The embryo 

 can be made out on the side of the grain facing the glume, as it is 



FlG. 2i. — A portion of the section of the grain of Andropogon Sorghum, x 500 

 P. pericarp: 1. seed-coat : A. aleurone layer; S. starch. 



outlined as an oval area. On the other face of the grain which is 

 towards the palea, the hilum is seen at the base. The grain varies 

 in shape considerably. It may be rounded, oval, ellipsoidal, narrow 

 and cylindrical, oblong terete or furrowed. There is considerable 

 variation as regards the colour also. 



