30 TREES OF THE NORTHERN UNITED STATES 
growth then form and often become quite large before 
autumn. 
There are many examples among the smaller plants, 
but rarely one among the trees, of indefinite annual 
growth; that is, the plant puts forth leaves and forms 
stems throughout the whole growing-season. The com- 
mon Locust, the ‘Honey-locust, and the Sumacs are illus- 
trations. 
Bups.— Buds are either undeveloped branches or un- 
developed flowers. They contain within the scales, which 
usually cover them, closely packed leaves; these leaves 
are folded and wrinkled in a number of different ways 
that will be defined at the end of this chapter. 
PosITION AND NumBer.—While the axils of 
the leaves and the ends of the stems are the 
ordinary places for the buds, there are many 
number, etc., that render them very interesting 
‘¢ for winter study. Sometimes there are several 
] to the single leaf. In the Silver Maple there are 
buds on each side of the true axillary one; these 
are flower-buds, and during the winter they are 
larger than the one which produces the branch. 
The Butternut (Fig. 14) and the Walnut have 
several above each other, the upper one being 
the largest and at quite a distance from the 
true axil. In these cases the uppermost is apt 
to grow, and then the branch is said to be extra- 
axillary. In the Sycamore the bud does not 
show while the leaf remains on the tree, as it is 
in the hollow of the leafstalk. In the winter 
the bud has a ring-like scar entirely around 
it, instead of the moon-shaped scar below as 
in most trees. The Common Locust has several 
buds under the leafstalk and one above it in 
peculiarities in regard to their exact position, °° 
