ECOLOGY OF LEAVES 



107 



usually with the space between the leaves a good deal 

 smaller than the areas of the leaves themselves, it is called 

 a leaf-mo saic. 

 Many of the most 

 interesting leaf- 

 groups of this sort 

 (as in the figure 

 above mentioned) 

 are found in the 

 so-called root- 

 leaves of plants. 

 Good examples of 

 these are the dan- 

 .delion, chicory, 

 fall dandelion, Fig. 72. Leaf Arrangement of Horse-Chestnut 

 thistle, hawk- on Vertical Shoots (top view). 



weed, pyrola, and plantain. How are the leaves of these 



plants kept from 

 shading each 

 other ? 



126. Much- 

 Divided Leaves. — 

 Not infrequently 

 leaves are cut into 

 slender fringe-like 

 divisions, as in the 

 carrot, tansy, 



southernwood, 

 Fig. 73. Leaf Arrangement of Horse-Chestnut 



on Vertical Shoots (side view). wormwood, yar- 



row, dog-fennel, 

 cypress- vine, and many other common plants. This kind 

 of leaf seems to be adapted to offer considerable surface to 



