80 PSINCIPLES OF PLANT CULTUBE 



deed, they may never push into growth. Some lateral 

 leaf-buds (131), especially those most distant from the 

 terminal bud, usually remain dormant, through want of 

 light or nutriment, and are overgrown by the enlarging 

 stem the following year. They are then called latent 

 buds. Stimulated by destruction or injury of the stem 

 above, dormant buds sometimes push into growth years 

 after their formation. 



We can usually decide whether detached dormant 

 shoots of trees and shrubs, as cions and cuttings, are of 

 the preceding year's growth or older, since, as a rule, only 

 wood formed the preceding year has visible undeveloped 

 buds. (Exceptions to this rule are not uncommon in 

 unthrifty trees and shrubs.) A bud, in pushing into 

 growth, consumes reserve food from the parent branch. 

 The more horizontal a branch the smaller is the supply 

 of water to its buds. 



130. Adventitious buds. — Although buds are nor- 

 mally formed only at the nodes of the stem, they may 

 under the stimulus of unusual water and food supply 

 (101) be formed without regard to nodes. The trunk 

 of a vigorous elm, willow or horse-chestnut tree, cut off 

 early in the season, often develops a multitude of buds 

 from the thickened cambium (68) at the top of the stump, 

 and a circle of shoots often spring up about the base of 

 a tree of which the top has been injured by over-pruning 

 or severe cold. Such buds are called adventitious. It 

 is, however, often difficult or impossible to distinguish 

 between adventitious and latent buds (129). 



The roots of many plants, as the plum, choke cherry 

 and raspberry, develop adventitious buds freely, espe- 

 cially when injured, a fact often utilized in propagation 

 by root cuttings (376). 



