68 PLANT LIFE. 



weak, and broad leaves of the Garlic. This does not 

 apply to those British Orchids which have underground 

 stores, for they generally flourish in wet and rather 

 barren places and only rarely in dry, rank grass. 



Fig. 7. — Taw^\ {Tanncetiun vulgarc L.). An autumn flowering herbaceous 

 plant. It shows the gradual unfolding and the erect bud position of the leaves 

 which are also finely divided. 



The fact that b?ilbs and conns are specially abundant 

 in dry climates makes it probable that dry heat 

 exercises some influence. Certain experiments have 

 also shown that heat actually increases the yield in 

 weight of potatoes. 



These stores of food are certainly a great advantage 

 to the plants which produce them. In South Africa 



