ITS GENERAL MORPHOLOGY. 



235 



increase in the number of the petals of double flowers is altogether 

 at the expense of the sta- 

 mens and pistils. In such 

 cases the petals themselves 

 are prone to double, or to 

 multiply in number. 



430. In full double But- 

 tercups we may often no- 

 tice a tendency of the ro- 

 sette of petals to turn green, 

 or to retrograde still far- 

 ther into foliaceous organs. 

 And there is a monstrous 

 state of the Strawberry- 

 blossom, well known in 

 Europe, in which all the 

 floral organs revert into 

 green sepals, or imperfect 

 leaves. The annexed il- 

 lustration (Fig. 272) exhibits a similar retrograde metamorphosis 

 in a flower of the White Clover, where the calyx, pistil, &c., are 

 still recognizable, although partially transformed into leaves. We 



may observe that the ovary, which has 

 opened down one side, bears on each 

 edge a number of small and imperfect 

 leaves ; much as the ordinary leaves, 

 or rather leaflets, of Bryophyllum are 

 apt to develope rudimentary tufts of 

 leaves, or buds, on their margins (Fig. 

 271), which soon grow into little plant- 

 lets. This reversion of a whole blos- 

 som into foliaceous parts has been 

 termed chlorosis, from the green color 

 thus assumed. 



431. Somewhat different is the ret- 

 rograde metamorphosis which is occa- 

 sionally seen in the production of a leafy branch from the centre of 



FIG. 272. A flower of the common White Clover reverting to a leafy branch, after Turpin. 



FIG. 273. Retrograde metamorphosis of a flower of the Fraxinella of the gardens, from 

 Lindley's Theory of Horticulture; an internode elongated just above the stamens, and bearing 

 a whorl of green leaves. 



