24 



BUDS OF POPLAR, ETC. 



[CH. 



The protection may be for a short time only, or it may 

 last for many weeks or months, as in the case of the 

 winter buds of most of our woody plants. In the former 

 case the leaves forming the bud are not much or even at 

 all different from the ordinary leaves of the shoot ; but in 

 the latter case the leaf-structures which protect the tender 

 tip of the shoot are often much altered in texture, form, 

 and other peculiarities, and are called bud-scales. 



The number of leaves, whether altered or not, which 

 enter into the formation of the bud, and their arrangement 



Fig. 17. Buds of Poplar, to the left, and Willow, to the right. The 

 former begins with one anterior scale (1), a stipule, wrapping round the 

 base of the bud : opposite to this is a posterior scale (2), the edges of 

 which overlap in front: a third scale shows at (3). The latter begins 

 with a double scale, representing two fused leaves ; the inner leaves of the 

 bud are bursting through (He). 



as regards one another, vary according to the species, and 

 the buds of different plants supply many characteristic 

 marks used in determining systematic position. 



