326 CALYX PERIANTH. [BOOK i. 



6. Of the Calyx. 



The calyx is the external integument of the Flower, con- 

 sisting of several verticillate leaves, either united by their 

 margins or distinct, usually of a green colour, and of a ruder 

 and less delicate texture than the corolla. 



Authors have long disputed about the definition of a calyx, 

 and the limits which really exist between it and the corolla : 

 the above, which is copied from Link, seems to be the only 

 one that can be considered accurate. In reality in many 

 cases they pass so insensibly into each other, as in Calycanthus 

 and Nymphsea, that no one can say where the calyx ends and 

 the corolla begins, although it is evident that both are present. 

 Linnaeus, indeed, thought that it was possible to distinguish 

 them by their position with regard to the stamens, asserting 

 that the divisions of the calyx are opposite those organs, and of 

 the corolla alternate with them ; but, if this distinction were 

 admitted, the corolla of the Primrose would be an inner 

 calyx, which is manifestly an absurdity. Jussieu defines a 

 calyx by its being continuous with the peduncle, which the 

 corolla never is ; and this may seem in some cases a good 

 distinction: but there are plenty of true calyxes, of all 

 Papaveraceous and Cruciferous plants, for instance, in which 

 the calyx is deciduous, and not more continuous with the 

 peduncle than the corolla itself. The only just mode of 

 distinguishing the calyx seems to me to be to consider it in 

 all cases the external verticillate series of the integuments 

 of the flower within the bracts, whether it be half-coloured 

 deciduous, and of many pieces, as in Crucifers ; membranous 

 and wholly-coloured, as in Mirabilis ; green and campanulate, 

 or tubular, as in Laurus and Lythrum. Upon this principle, 

 whenever there is only one series of floral integuments, that 

 series is the calyx. A calyx, therefore, can exist without a 

 corolla; but a corolla cannot exist without a calyx, either 

 perfect or rudimentary. 



The term Perianth is sometimes given as synonymous 

 with calyx ; but this is an error. 



The word Perianth signifies the calyx and corolla com- 



