TRANSPIRATION. 



155 



vertical instead of parallel with the ground, the 

 stomata are on both sides of the leaf. 



FIG. 42. COMPASS PLANT (Silphium laciniatum), 

 I. Seen from the East. 2. Seen from the South. 



An excellent example of this is the Compass 

 Plant (Silphium laciniatum, Fig. 42) of the Western 



