LEAVES 



11 



are the largest, and the upper leaves gradually diminish 

 in size. 



(3) Rosette-habit. An extreme case of crowding is shown 

 by plants with the rosette-habit ; that is, those which produce 



A B 



FIG. 6. Rosette-habit shown by mullein (A) and evening-primrose (B). 



a cluster or rosette of leaves at the base of the stem (Figs. 

 6 and 7). Often this rosette, frequently lying flat upon the 

 ground or upon the 

 rocks, includes all 

 the leaves the plant 

 produces. Ifhis close 

 overlapping of leaves 

 is a poor adjustment 

 to light at best, but 

 there is evident an 

 adjustment to se- 

 cure the most light 

 possible under the 

 circumstances. The 



lowest leaves of the ^ 7 _ Rosette . habit 9hown hy shepherd . 8 purse . 

 rosette are the long- 

 est, and the upper ones become gradually shorter, so that 

 each leaf has at least a part of its surface exposed to light. 



