212 THE bTOllY OF THE PLANTS. 



stems, usually growing in tufts together, and 

 each crowned by a single large fluffy yellow 

 flower-head. These stems are covered below 

 by short purplish scales ; and their purple 

 colouring matter enables them to catch and 

 utilise to the utmost the scanty sunshine that 

 falls upon the plant in chilly March weather. 

 For this particular colouring matter has the 

 special property of converting the energy in 

 rays of light into heat for warming the plant. 

 The scape is also wrapped up in a sort of 

 cottony wool, which helps to keep it warm ; and 

 the unopened flower-head turns downward at 

 , first for still further safety against chill or 

 injury. These various devices enable the colts- 

 foot to blossom earlier in the season than almost 

 any other insect-fertilised flower, and so to 

 monopolise the time and attention of the first 

 flower-haunting March insects. 



Coltsfoot is a composite by family ; so its 

 flowers are collected together into a head, after 

 the ancestral fashion, and enclosed by an in- 

 volucre which closely resembles a calyx. But 

 the type of flower-head differs somewhat from 

 that in any of the composite plants I have 

 hitherto described for you, because its outer 

 florets are not flat and ray-shaped, but strap-like 

 or needle-shaped. The inner florets, however, 

 are bell-shaped, and much like t^^ose of the 

 coDunon daisy. The naked scapes, each re- 

 sembling to the eye a shoot of asparagus, and 

 each crowned by a single fluffy yellow flower-head, 

 are familiar objects on banks or railway cuttings 

 in the first days of spring ; I have known them 



