74 



GROWTH AND WORK OF PLANTS 



On vigorous shoots the annual growth can be determined by the 

 presence of a band of small rings which mark the scale scars of 

 the previous year's bud. The leaf scars on the shoot are very 

 peculiar in form ; they are somewhat triangular 

 in outline. Upon the gray face of the scar 

 are several dark marks, a V-shaped mark below, 

 and a small round dot at each upper angle, 

 giving to the scar the grotesque appearance of 

 the face of some animal. These marks are 

 the scars of the fibre-vascular bundles which 

 extended into the leaf. Directly above each 

 leaf scar is a bud. This is the bud which was 

 formed in the axil of the leaf. Often above 

 this is another bud, a supernumerary, or ac- 

 cessory, bud. The position of the scars shows 

 that the leaf arrangement is alternate and 

 spiral, for a string passed around the stem and 

 passing over each leaf scar would extend in a 

 spiral. The bud scales occupy similar posi- 

 tions, but they are very much crowded. 



116. Shoots of the peach. The shoots of 

 the peach tree have a shiny, smooth surface, 

 which is usually reddish or reddish green in 

 color. The extent of the year's growth varies 

 from a few inches to several feet in length, 

 according to the position of the shoot on the 

 tree and the vigor of growth. The buds in the 

 axils of the leaf are one to three on vigorous 

 shoots, usually three. The middle one repre- 

 sents the main shoot; the lateral ones are 

 branches from its base. Often the lateral ones 

 develop shoots also, but when they are much 

 stouter than the middle one they are usually 

 flower buds. If not killed by extreme winter cold (say, 26 

 C.= 15 F. or lower), they will blossom in the spring. If 

 they have been killed, the flower is black. This can be seen by 



Fig. 65. 



Shoot of sumac. 

 Note axillary termi- 

 nal bud by side of 

 dead base of terminal 

 portion and dead leaf. 



