A TEXTBOOK OF BOTANY 



|rn. Ill, 9 



Another special form and function of leaves is represented 

 in tlie brown bud scales which enwrap the wint(>r l>uds of 

 our trees. They mostly lack chlorophyll, their cell walls 

 become thick and well cutinized, and often they develop 



xV/ 



Fi.i. 51. — Form.s of leaf tendrils; X '. Pea. Sniilax, BiKuonia. Clcmati,?, 

 Lathijrus Aphaca. The apparent leave.s of the hitter are stipules. 



coatings of resin or hairs ; and they fall away as the buds un- 

 fold. In some kinds each scale is an entire leaf, in others 

 it is a petiole \vith blade suppressed (Fig. 53), or it may lie a 

 stipule, as conspicuous in Tuli]i tree, where together the pair 

 forms a close-fitting cap (Fig. 57). 



