194 OF THE COROLLA. 



The knowledge of the real use of leaves, see chapter 

 16, may however throw some light upon that of the 

 calyx. Besides protection of the flower from external 

 injuris?, which is one evident use of this part, it appears 

 highly probable that it may often contribute to^the 

 growth and strength of the stalk which supports it, as 

 the leaves do to that portion of branch below them. 

 The stalk often swells considerably during the growth 

 of the flower, especially just below the calyx, becoming 

 more woody, an alteration frequently necessary for the 

 support of the ripening fruit. When the calyx falls 

 very early, as in the Poppy tribe, Papaver and Glau- 

 cium, I cannot find that the flower-stalk is subsequently 

 enlarged, nor in any manner altered ; while in genera 

 without number, whose calyx is permanent, the stalk 

 becomes not only more woody, but often considerably 

 thickened. 



II. COROLLA. The Corolla, vulgarly called the leaves 

 of the flower, consists of those more delicate and 

 dilated, generally more coloured leaves, which are 

 always internal with respect to the calyx, and con- 

 stitute the chief beauty of a flower. In the Rose 

 the Corolla is red and fragrant ; in the Violet pur- 

 ple ; in the Primrose yellow. 



This term includes two parts, the Petal, Petalum, 

 and the Nectary, Nectarium. The former is either 

 simple, as in the Primrose, in which case the Corolla 

 is said to be monopetalous, of one petal ; or com- 



