BUTTERCUP EVOLUTION 



In the first place I will ask the reader to glance 

 at Fig. 1 01 (Plate 72). There some of the famihar 

 meadow buttercups are shown, but careful inspec- 

 tion of the illustration will reveal two distinct 

 kinds of flowers. The buttercups that first appear 

 and paint the meadows golden in early summer are 

 a distinct species from those that develop a month 

 later. The flowers of the two species, however, 

 closely resemble each other, and as one species 

 quickly succeeds the other, the change is but rarely 

 observed except by botanists. 



The smaller flowers in the illustration will be 

 seen to have their five sepals pressed against their 

 coloured petals, but the larger flowers have theirs 

 held back away from the petals and pressed 

 against the stem. A glance at the roots of the 

 two species will reveal a more striking difference 

 (Fig. 102, Plate 73). The root of the species bear- 

 ing the smaller flowers is shown on the left, and 

 that bearing the larger ones on the right. The 

 latter is the Bulbous Buttercup (Ranunculus bulb- 

 osus), which is the first to appear in early summer. 

 Its bulbous root explains its earlier appearance, for, 

 throughout the winter months nourishing starches 

 and food materials are stored therein which enable 

 it to get an early start : and so it steals a march on 

 its neighbour the Meadow Buttercup or Crowfoot 

 (Ra7iimcnlus acris), which is forced to gather most 

 of its building material as it requires it. 



Also, the bulbous buttercup rarely needs to 

 grow more than a foot in height, because at the 

 time when it holds up its flowers the grasses have 



173 



