CHAP. H. 



COROLL.U 



139 



appendai/es, and such a calyx is said to be apimidicalate ; bm 

 Moeiich has proposed a particular term for them, peraphijUum, 

 which is, however, never used. 



88 



7. Of the Corolla. 



89 90 



That envelope of the flower which forms a second whorl 

 within the calyx, and between it and the stamens, is called the 

 corolla. Its divisions always, . without exception, alternate 

 with those of the calyx, and are called petals. Like the 

 sepals, they are either united by their margins, or distinct; 

 but, unlike the calyx, they are rarely green, being for the most 

 part either white, or of some colour, such as red, blue, or 

 yellow, or of any of the hues produced by their intermix- 

 ture. The corolla is generally also much larger than the calyx. 



Necker called the corolla jjerigynandra interior^ and Lin- 

 naeus occasionally gave it the name of Aulceum, which literally 

 signifies the drapery of a room. 



The alternation of the segments of the corolla with those 

 of the calyx is a necessary consequence of their both being- 

 modifications of whorls of leaves, and therefore subject to the 

 same laws of arrangement. If two whorls of leaves are exa- 

 mined, those of Galium, for example, they will always be 

 found to be mutually so arranged, that if the internode that 

 separates them were removed, they \\ould exactly alternate 

 with each other ; and as there are no known exceptions to this 



