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TEXTBOOK OF BOTANY 



Branches usually do not grow from the lateral buds of the palm, and the 

 growth of the terminal bud alone results in an unbranched stem or 

 trunk with a crown of leaves at its summit. Such a stem is said to be 

 columnar (Fig. 86). 



Fig. 86. Columnar stems of the cabbage palmetto. Photo from U. S. Forest Service. 



A dominant terminal bud is present in spruce. Each year the main 

 stem increases in length, and from the lateral buds branches grow out- 

 ward, forming a whorl at the apex of the previous year's growth. The 

 type of branching which results in a prominent main stem that extends 

 beyond the smaller lateral branches is referred to as excurrent branch- 

 ing(Fig.87). 



In contrast to the spruce, the terminal buds of the elm are tempo- 

 rary. Since all branches of an elm develop from lateral buds, the main 

 stem appears to be repeatedly divided and subdivided until it is lost in 

 the crown of the tree. The tree trunk is ultimately terminated by in- 

 numerable branchlets, and this suggested the name, deliquescent branch- 



