10 



Bulletin 194 



form an important article of diet for the birds and small animals of 

 VI. WINTER TWIG the forest. Unfortunately there are a number 

 of limitations to the usefulness of fruit for iden- 

 tification purposes. Some trees require years to 

 mature their fruit. Many trees, wnile producing 

 an abundance of fruit at certain mtervals, bear 

 none at all or only very small and uncertain quan- 

 tities between the years of abundance. Again, m 

 the case of dioecious trees, only the female or 

 pistillate bear fruit. Notwithstanding these limi- 

 tations tree fruits are a very valuable aid to the 

 student, and he should always search closely for 

 evidences of their presence and character. 



Winter-buds. — Buds, with their accompany- 

 ing leaf- and stipule-scars, form the basis of tree 

 identification in winter. The size, color, position 

 with reference to the twig, number and arrange- 

 ment and character of bud-scales, etc., all are 

 characters of the greatest value in winter deter- 

 minations. Buds either are terminal or lateral, 

 depending on their position on the twig. A 

 lateral bud is one situated on the side of a twig 

 in the axil of a leaf-scar. A terminal bud is 

 one situated at the end of a twig, where it is 

 ready to continue the growth of the twig the 

 following spring. To the presence or absence 

 of the terminal bud is accorded much importance 

 in the keys on pages 162 and 163, which enable 

 one more surely to identify a tree. Inasmuch as the determination of 

 this point gives the beginner some trouble at first, it is hoped that the 

 accompanying diagrams and explanatory remarks will serve to make 

 the distinction clear. 



In the elms, willows, basswood and many other species the ter- 

 minal bud and a small portion of the tip of the twig dies and drops ofif 

 in late autumn, leaving a small scar at the end of the twig (a, fig. vi). 

 The presence of this tip-scar indicates that the terminal bud is absent. 

 Often a lateral bud will be found very close to the tip-scar (b, fig. vi), 

 which, bending into line with the twig, makes it appear to be a terminal 

 rather than a lateral bud. However, the presence of a leaf-scar im- 

 mediately below it shows it to be a lateral bud (c, fig. vi). The 



Tip-scar. 

 Lateral bud. 

 Leaf-scar. 

 Stipule-scars. 



