LIFE HISTORIES OF FAMILIAR PLANTS 



to be. Each of the plants mentioned had a 

 simple buttercup origin, but so altered have 

 they become that we no longer recognise them 

 as buttercups. 



The distinguishing features of the typical but- 

 tercup flower are these : it should have five 

 separate sepals, five separate petals, numerous 

 stamens in whorls of five, and numerous carpels, 

 or ovaries, also in whorls of five, and the stamens, 

 petals, and sepals should all arise below the 

 central group of ovaries. Also, each of the petals 

 has, near its base, a simple honey gland covered 

 with a tiny scale. 



Now, in some of the more evolved genera of 

 the Buttercup family, as in the clematis (Fig. 104, 

 Plate 75), the anemone, and the marsh marigold, 

 we find but a single coloured whorl around their 

 stamens and ovaries. Apparently these flowers 

 have lost the five green sepals of their calyx ; 

 however, that is not the case, it is their petals 

 which have disappeared. In the course of their 

 evolution their petals have become more and more 

 insignificant until they have been completely lost. 

 But the most curious part of the matter is that 

 with the loss of their petals the sepals have 

 become coloured — i,e.j taken on the functions of 

 the petals. 



This feature of the suppression of the petals 

 and the promotion of the sepals is, when one comes 

 to think of it, very extraordinary. Why should 

 several genera in the Buttercup family that re- 

 quired coloured display to attract fertilising insects^ 



178 



