324 



NEW ENGLAND TEEES IN WINTER. 



|-tr 



Most species by the end of the growing season have formed 

 terminal buds which remain through the winter and are destined 

 to continue the growth the following spring. In 

 some species, however, such as the Mulberry (fig. 8) 

 the terminal bud together with the tip of the twig 

 dies away and drops off before the beginning of winter 

 leaving a small scar at the end of the twig. The 

 presence or absence of the terminal bud is a very 

 valuable point of distinction and is used throughout 

 in the keys. Unfortunately it is not always possible 

 at a cursory glance to say whether the terminal bud 

 is present or absent and a hand-lens must generally 

 be used for an accurate determination of this point. 

 In the Mulberry figured, the self -pruning scar formed 

 by the dropping off of the terminal 

 bud is perched on the tip of the twig 

 with the topmost lateral bud obvi- 

 ously in the axil of the last leaf -scar. 

 Frequently, however, the self-prun- 

 ing scar may be nearer the lateral 

 bud which bends in and gives the 

 appearance of being terminal. The 

 pig. e-Twig of presence of a leaf-scar below it 



Butternut. .... . , .-,-, 



tr terminal bud. snows that it is in iact axillary, 



xillary bud. . .. . 



but since leaf-scars are sometimes 

 present toward the end of twigs without buds in 

 their axils the presence of the self -pruning scar at 

 the twig end must be used as the decisive sign that the terminal 

 bud is really absent. 



Aside from the color, the presence or absence of hairs, stickiness, 

 fragrance and other such surface characters, the position of the 

 buds in relation to the twig may be of importance. Buds that lie 

 close up against the twig as those of the Small-toothed Aspen 

 (p. 389) are called appressed, while those that project more or 

 less away from the twig as those of the Carolina Poplar 

 (fig. 5) are called divergent. In the Common Locust 

 and a few other forms the buds are sunken below the surface of the 

 twig, and can be found only by cutting the twig lengthwise 

 through the leaf-scar. 



s p Superposed 

 accessory bud. 

 p chambered 



pith. 



Fig. 7 Twig of Red 

 Maple. 



ax axillary bud. 



cl collateral acces- 

 sory bud. 



