172 THE FLOWER. 



buttercups. 1 In these the green hue of the centre of the rosette 

 indicates a tendency to retrograde a step farther into sepals, or 

 into a cluster of green leaves. This takes place in certain blos- 

 soms of the Strawberry, the Rose, &c. Such production of 

 " green roses," and the like, has been appropriately called 

 chlorosis, or by Masters chloranthy, from the change to green. 

 309. A monstrosity of the blossom of White Clover, long ago 

 figured by Turpin (Fig. 319), is such a case of foliaceous rever- 

 sion, in which even the ovules are implicated. 

 The imperfect leaves which take the place of 

 the latter may be compared with the leafy 

 tufts which form along the margins of a leaf 

 of Bryophyllum, by which the plant is often 

 propagated. (Fig. 322.) 



310. The reversion of a simple pistil di- 

 rectly to a leaf is seen in the Double-flowering 

 Cherry of cultivation (Fig. 320, 321), usually 

 passing moreover, by prolification of the re- 

 ceptacle, into a leafy branch. 



311. The reversion of pistils to stamens is 

 rarer, but has been observed in a good number 

 of instances, in Chives, in the Horseradish, 



in Gentians and Hyacinths, and in some Willows. In the 

 latter, the opposite transformation, of stamens to carpels, is 

 very common, and curious grades between the two are met with 

 almost every spring. So also in the common Houseleek, and 

 in perennial Larkspurs. Certain apple-trees are known, both 

 in the United States and Europe, in which, while the petals are 

 changed into the appearance of minute green sepals, the outer 

 stamens are converted into carpels, these supernumerary and 

 in the fruit superposed to the five normal carpels. 2 In Poppies, 

 many of the innermost stamens are occasionally transformed 

 into as many small and stalked simple pistils, surrounding the 

 base of the large compound one. 



1 It must not be concluded that the supernumerary petals in all such cases 

 are reverted stamens, or stamens and pistils. Some are instances of abnormal 

 pleiotaxy, i. e. of the production of one or more additional ranks of petals 

 (better deserving the name of double flower}, with or without reversion of 

 essential organs to flower-leaves. 



8 These trees are popularly supposed to bear fruit without blossoming; 

 the reverted green petals being so inconspicuous that the flower is un- 

 noticed. 



FIG. 320, 321 . Green leaves from the centre of a blossom of Double-flowering Cherry, 

 one still showing, by its partial involution and its style-like apex, that it is a reverted 

 carpel, the other a small but well-formed leaf. 



FIG. 322. Leaf or leaflet of Bryophyllum, developing plantlets along the margins. 



