OPENING OF BUDS 



205 



In plants, like annuals and those that live in the tropics, the 

 buds usually have no protective scales and are called naked buds. 

 Scaly . buds are characteristic of plants which 

 must pass through seasons that are unfavor- 

 able for growth, and may be considered a 

 device for maintaining partially developed 

 stem portions in a protected state, and in 

 readiness to assume rapid growth at the 

 opening of the growing season. 



Opening of Buds. 

 The bud scales are forced 

 open by the growth of 

 the young shoot within. 

 The resumption of 

 growth by the parts en- 

 closed is first shown by FlG ig3. Flower 

 the swelling of the bud. bud of the Pear, in 

 When the young shoot which the flowers are 

 resumes growth at the pushing the scales 

 beginning of the grow- 

 ing season, it grows with 

 remarkable rapidity and 

 in a few days pushes out of its scaly cover- 

 ing. (Fig. 183.) After the shoot has es- 

 caped, the scales usually fall off, leaving a 

 scar about the branch at their place of at- 

 tachment. The bud has now disappeared 

 and in its place there is a new growth bear- 

 ing leaves or flowers, or sometimes both. 



The scars left by the scales remain until 

 the bark is sufficiently developed to obscure 

 them, and serve to indicate the age of the 

 different regions of a branch. In Figure 



of different ages as in- 1$4, the portion beyond the scar (a) is the 

 dicated by the scars re- last season's growth. The portion between 

 suiting from the falling ( a ) anc j (&) i s two years old, and the por- 

 tion between (&) and (c) is three years of 

 age. Thus the age of a given region of 

 a branch is indicated by the scars on the branch as well as by 

 the annual rings in its woody cylinder. 



-- C 



FIG. 184. Plum 

 branch showing regions 



away of the bud scales. 

 Described in text. 



