TWO ENTIRE FLOWERS SHOWING PET ALIZATION 



Views of two flowers of tlic Japanese Quince, Cydonia japonica, sliowing the extent to which 

 petaHzation takes place on the individual flowers. Remnants of anthers may be seen on 

 some of the petals, while close scrutiny will reveal slight petaHzation of some of the anthers. 

 (Fig. 6.) 



not ordinarily realized. Complete inter- 

 ^radations may be worked out from the 

 bracts en\'eloping the flower bud to the 

 whorl of stamens. Thus in the cactus 

 flower it is practically impossible to say 

 where the enveloping bracts stop and the 

 sepals commence. Likewise in the 

 white water lily one cannot distinguish 

 where the sepals stop and petals begin. 

 Similarly, in the flower of the Ja])anese 

 quince (Cydonia japonica). here illus- 

 trated, there is a complete intergrading 

 of the petals and stamens, there being 

 no distinct line of demarcation between 

 these two sets of plant structures. An 

 examination of the accomi)an\'ing illus- 

 tration will reveal the interesting fact 

 that stamens may be found half of which 

 are in the form of ]jetflls, and petals may 

 be seen jjartly in the form of stamens. 

 The integrading is so comi)lete that 

 entire petals are present containing what 

 appear to be but the remnants of an 

 anther on the top. 



A similar ])henomenon is exhibited in 

 many double flowers as, for instance, in 

 double roses. By means of cultivation, 

 man has succeeded in changing the 

 stamens and pistils of completely double 

 flowers into petals. That the pistils 

 react similarly is demonstrated in wild 

 plants by certain s]3ecies of Trillium and 

 in cultivated plants by roses and cher- 

 ries; in these i)lants the pistils occasion- 

 ally are transfonned into green leaf-like 

 structures. 



In order to create flowers with a large 

 number of petals by means of cultiva- 

 tion, it is obvious then that a ])lant 

 should be selected for experimentation 

 containing a large number of stamens, a 

 ])lant such as the wild rose, l)tiUercup, 

 or straw1)erry. The process is techni- 

 cally tenned petalody or jietalization. It 

 seems to be aided, as is suggested by the 

 petaHzation of tulips, by the presence 

 of abundant nutrition, i)articularly the 

 l)resence of nitrogenous substances. 



