ATTACHMENT OF LEAF AND PETIOLE 



113 



docks, and sorrels, is technically known as an 

 ocrea (that is, a "boot"). It is considered to be 

 formed of the union of two stipules. 



124. Observe the manner in which the petiole 

 is attached to the blade of the leaf. In the bar- 

 berry (Fig. 99) it is gradually merged into the 

 blade. Such a leaf is described in terms of the 



Fia. 111. 

 Peltate leaf of moonseed. 



Fig. 112. 

 Peltate leaf of nasturtium. 



blade ; that is, the blade is said to be narrowed 

 into the petiole. Observe the attachment in the 

 maple, grape, and apple leaves. In them — and per- 

 haps in the greater number of leaves — the attach- 

 ment of the petiole is more or less definite, and 

 is made to the edge of the blade. 



