iv ON PLANT LIFE 155 



BEHAVIOUR OF LEAVES IN RAIN 



The behaviour of plants with reference to 

 rain affords many points of much interest. 

 The Germander Speedwell (Veronica) has two 

 strong rows of hairs, the Chickweed (Stellaria) 

 one, running down the stem and thus conduct- 

 ing the rain to the roots. Plants with a main 

 tap-root, like the Radish or the Beet, have 

 leaves sloping inwards so as to conduct the 

 rain towards the axis of the plant, and con- 

 sequently to the roots ; while, on the contrary, 

 where the roots are spreading the leaves slope 

 outwards. 



In other cases the leaves hold the rain or 

 dew drops. Every one who has been in the 

 Alps must have noticed how the leaves of the 

 Lady's Mantle (Alchemilla) form little cups 

 containing each a sparkling drop of icy water. 

 Kerner has suggested that owing to these cold 

 drops, the cattle and sheep avoid the leaves. 



