The Wanderings of the Groundsel. 87 



and because they did not form an unbroken surface they were 

 much more effective than a purely sail-like mechanism/ These 

 hairs, now called the pappus, made it possible for even a slight 

 breeze to blow the light fruits to considerable distances. 



The groundsel, therefore, may be said to have been originated 

 by the uplifting of the Andes, and it proved eminently suited for 

 the arid windy mountainous regions, where it still flourishes in 

 gi-eat profusion. Senecio was, in fact, developed by the 

 mountains with the mountains for the mountains. It arose by 

 the modification of certain Amazonian Lobelioids towards the 

 end of the Cretaceous Period, and started out on its many and 

 long wanderings with an equipment of structure and constitution 

 which was pre-eminently suited for mountaineering. As a 

 natural consequence it usually took the "high" road in its travels. 



Being spread by the wind both up and down the mountain 

 slopes it reached to snow-level on the one hand and to the bush 

 country around the forests on the other, and it naturally under- 

 went corresponding changes. Near the snow-level it became even 

 more densely compact and much more hairy, giving rise to the 

 edelweiss and cudweed type. On the lower slopes, which were 

 both warmer and more moist, the hairs of the pappus ceased to 

 be developed as such and underwent various changes into awns 

 and barbs which proved to be advantageous for dispersal by forest 

 animals. Thus the groundsel gave rise to the bur-marigold and 

 sunflower type. With these two South American progeny it then 

 moved along the Andes southwards to Tierra del Fuego, and 

 northwards to where the Rockies were beginning to appear in 

 what are now the United States and Mexico. 



On reachiiig the southern part of the Rockies Senecio 

 developed, in part, long appendages to the style branches and 

 became slightly modified in other ways, giving rise to the golden- 

 rod and Michaelmas daisy type. By this time the Eocene Period 



1 For details of tliis point and the general proofs (including the geological evidence 

 and records of fossils), for the whole of this account see "The Origin and Develop- 

 ment of Conipositie." Wesley. London, 1919. 



