266 SHADE PLANTS OF THE ALPINE FORESTS 



shining black internal coat. Thus the Wood Sorrel 

 presents the curious case of a seed shooting itself off 

 from the parent fruit by sacrificing one of its seed- 

 coats. We have already seen how in the Field 

 Pansy (p. 162) a similar effect is attained in quite a 

 different way. 



THE ALPINE LETTUCE. 



Everyone is familiar with our British Coltsfoot 

 (Tussilago farfara, Linn.), so common on dry bare 

 slopes, such as newly-made railway embankments, 

 where it is often the first plant to obtain a footing. 

 The pale yellow flower-heads of this weed appear 

 in spring, some little time before the large, broad, 

 heart-shaped leaves. 



In Alpine Switzerland the Coltsfoot is not very 

 abundant, though, as with us, it is common enough in 

 the plains. It is then replaced by another near rela- 

 tive, the Alpine Lettuce (Homogyne alpina, Cass., 

 natural order Composite, the Composite family). 

 Such replacements will be frequently noticed within 

 the Alpine zone. Our Common Daisy (Bellisperennis, 

 Linn.) is replaced by the Alpine Daisy (Bellidastrum 

 michelii, Cass.), while in the High Alpine region the 

 Alpine Ox-eye Daisy (Chrysanthemum alpinum, Linn.) 

 takes the place of the Common Ox-eye Daisy (C. leu- 

 canthemum, Linn.) of the Alpine, Subalpine, and Low- 

 land zones. 



The Alpine Lettuce is, however, a very different 

 plant to the Coltsfoot. It is essentially a shade plant, 



