OP THE COROLLA. 251 



Phyllody of the corolla. The petals also are frequently 

 replaced by leaves, though in many of the recorded 

 mstances the change has been one of colour only; 

 these latter are strictly cases of virescence. M. Seringe^ 

 speaks of a flower of Peltaria alliacea in which the 

 calyx was petal-like, while the corolla was leafy as if 

 there had been transposition of the two organs, a very 

 rare, if not unparalleled, instance. In a flower of 

 Campanula: Medium, provided, as is often the case, 

 with a double corolla, the outer corolla was slit down 

 on one side, the edges of the cleft being leafy. 



Fig. 133. Sepals and petals to leaves. Geranium. 



The frondescent petals are very often completely dis- 

 joined, as in Verhascum nigrum, and Lonicera Peri- 

 clymenum, in which, moreover, median prolification 

 generally coexists. In the case of Tropceolum majus, 

 the ordinary leaves of which are peltate and orbicular, 

 the petals when frondescent have not the peltate 

 arrangement, but are spathulate, and provided with 

 very long, narrow stalks, so that, in some cases, they 

 are, more properly speaking, enlarged virescent petals 

 than true leaves; in other instances, however, the 

 arrangement of the veins is more like that of the true 

 leaves than that of the petals. 



As might be expected, frondescence of the petals is 

 frequently accompanied by other changes of a similar 

 nature in other parts of the flower, and sometimes by 

 the abortion of the sexual organs. Thus, in Adwa 

 spicata, as observed by Fresenius, the petals were 

 replaced by true petiolate, palminerved, lobed leaves, 



' ' Bull. Bot.,' i, p. 6. 



