The External Features of Stems 123 



W. S. Cooper 

 Fig. 70. A deliquescent monocot (the tree yucca, Yucca arborescens), photographed at 

 Cajon Pass, California. The dehquescent type of stem is unusual among the monocots. 



divides until it is lost in the crown of the tree. The gradual 

 dissolving of the trunk into a spray of terminal branchlets sug- 

 gested the name deliquescent (Latin : deliquescens, dissolving) 

 for this type of stem (Fig. 69) . 



We see, therefore, that the excurrent type of stem depends on 

 the continual development of terminal buds, while the deliques- 

 cent type depends on the growth of lateral buds. The form of 

 plants in cultivation may be modified by trimming them, and so 

 forcing the growth of certain buds. Lawn trees and shrubs are 

 grown either for shade or for ornamental effects. We secure 

 shade by trimming off the terminal buds and so causing many 

 of the lateral buds to develop into branches and thus form a 

 denser crown. Ornamental effects are secured by trimming 

 plants so that they will be in artistic harmony with their 

 surroundings. 



Fruit trees and grapes have been found to produce more fruit, 

 and fruit of a better quality, when the number of branches is 

 limited. A smaller number of branches on a tree secures an 

 open crown and permits the sunlight to penetrate to every leaf, 



