CHAPTER XII. 

 BUDS AND LEAVES 



BUDS 



Buds are classified according to their nature, class, posi- 

 tion, arrangement and relation to the stem. 



Nature. Buds are either (1) scaly or (2) scaleless. 



1. Scaly Buds. Most buds are protected by several layers 

 of imbricate scales. These scales are frequently quite leaflike 

 in structure, and differ greatly in form and size, even on the 

 same bud. The outer scales, as in horse-chestnut, are short 

 and broad, while the inner scales are much larger and are 

 longer than broad. In the study of buds the number and 

 rows of scales should be considered. Scales are smooth when 

 they are free from outgrowths; resinous w r hen they are 

 coated with resin, as in horse-chestnut and balm of gilead; 

 hairy when the epidermis develops hairs. When a scaly bud 

 finally develops into a leaf or flower, the scales fall away 

 from the twig and leave scars which clearly mark the loca- 

 tion of the bud and which may be utilized to determine the 

 age of the twig. The space from the apical or lateral bud to 

 the first ring of scars represents one year's growth, to the 

 second ring of scars two year's, to the third three year's, etc. 



2. Scaleless Buds are not common in northern climates; 

 in the tropics, however, many plants develop buds without 

 an outer protective scaly covering. 



Classes. There are three classes of buds, namely; leaf- 

 buds, flower-buds and mixed buds. Leaf-buds contain one or 

 more rudimentary leaves; flower buds contain only a rudi- 



