CHAPTER V. BUDS AND BRANCHES 



I. MODES OF BRANCHING 



Material. — For determinate growth, have twigs of an alternate and 

 an opposite-leaved plant showing well-developed terminal buds: hickory, 

 sweet gum, cottonwood, poplar, chestnut, are good examples of the 

 first ; maple, ash, horse-chestnut, viburnum, of the second ; for the two- 

 forked kind, mistletoe, buckeye, horse-chestnut, jimson weed, lilac. For 

 showing indefinite growth : rose, willow, sumach, and ailanthus are good 

 examples. Gummy buds, like horse-chestnut and poplar, should be 

 soaked in warm water before dissecting, to soften the gum ; the 

 same treatment may be applied when the scales are too brittle to be 

 handled without breaking. Buds with heavy fur on the scales cannot 

 very well be studied in section; the parts must be taken out and 

 examined separately. 



144. Modes of branching. — Compare the arrangement 

 of the boughs on a pine, cedar, magnolia, etc., with those 



of the elm, maple, apple, or any of our 



common deciduous trees. Draw a diagram 



of each, showing the two modes of growth. 



The first represents the 



excurrent kind, from the 



Latin excurrere, to run 



out ; the second, in which 



the trunk seems to di- 

 vide at a certain point 



and flow away, losing 



itself in the branches, 



is called deliquescent, 



from the Latin deliques- 



cere, to melt or flow away. 

 The great majority of stems, as a little observation will 

 show, present a combination of the two modes. 



131 



Fig. 147. — Dia- 

 gram of excurrent 

 growth. 



Fig. 148. — Diagram 

 of deliquescent growth. 



