CHAP. II. 



COROLLA. 



143 



phaea, Niipbar, Magnolia, SiC. It sometimes happens that, if 

 there is more than one row of petals, all within the first row 

 assume a different appearance from the first ; the filamentous 

 processes of the crown of Passiflora are also apparent!}' of this 

 nature. 



Tlie petals are often furnished with little appendages 

 {fig. 105.)i which are either inner rows of petals in a state of 

 adhesion to the first row, or modified stamens; which it is 

 sometimes difficult to ascertain, but always certainly one of 

 the two. Many of these enter into Linnosus's notion of nec- 

 tarium, although nearly the whole of them are destitute of 

 any power of secreting nectar or honey. 



101 



100 



102 



103 104 105 



The most common form of appendage is the corona, which 

 proceeds fi'om the base of the limb, forming sometimes an undi- 

 vided cup, as in Narcissus {fig. 104.), wlien it becomes the 

 scyphus of Haller ; sometimes dividing into several foliaceous 

 erect scales, as in Silene and Brodi^a, when it forms the lamella 

 of some writers; occasionally appearing as cylindrical or clavate 

 processes, as in Schwenckia and Tricoryne, where it is mani- 

 festly modified stamens; and even in some instances formino- 

 a thick solid mass covering over the ovarium, and adherino- to 

 the stamens, as in Stapelia ; when it is called the orhiculus. 

 Parts of this last form of corona bear several names, w^hich 

 are found useful in avoiding repetition in describino- the com- 

 plicated structure of this kind of appendage. Tlie whole mass 

 of the corona is the orhiculus, or saccus, or stylotegium ; cer- 



