90 



ESSENTIALS OF BOTANY 



Most of the buds so far considered were leaf-huds, that 

 is, the parts inside of the scales would develop into leaves, 

 and their central axes into stems ; but 

 some were mixed buds, that is, they con- 

 tained both leaves and flowers in an 

 undeveloped condition. 



Flower-buds contain the rudiments of 

 flowers only. 



Sometimes, as in the black walnut and 

 the butternut, the leaf-buds and flower- 

 buds are readily distinguishable by their 

 difference in form, while in other cases, 

 as in the cultivated cherry, the differ- 

 ence in form is but slight. 



The rings of scars about the twig, 

 shown in Fig. 54, mark the place where 

 the bases of bud-scales were attached. 

 A little examination of the part of the 

 twig which lies outside of this ring will 

 lead one to the conclusion that this 

 portion has all grown in the one spring 

 and summer since the bud-scales of that 

 particular ring dropped off. Following 

 out this suggestion, it .is easy to reckon 

 the age of any moderately old portion of 

 a branch, since it is equal to the num- 

 ber of segments between the rings. In 

 rapidly growing shoots of willow, pop- 

 lar, and similar trees, 5 or 10 feet of 

 the length may be the growth of a single year, while in the 

 lateral twigs of the hickory, apple, or cherry the yearly 

 increase may be but a fraction of an inch. Such fruiting 



Fig. 51. Accessory 

 Buds of Butternut. 

 (Reduced.) 



/, leaf -scar ; ax, axil- 

 lary bud ; a, a', ac- 

 cessory buds ; t, ter- 

 minal bud. 



