BUDS AND BRANCHES 121 



bud grows somewhat in the line of the original axis, the 

 terminal bud of this branch in turn dies, and is pushed 

 aside by the next lower lateral bud. Thus the process 

 is repeated, and a series of branches is superposed one on 

 another in such a way as to resemble a simple axis. Such 

 a branch system is called a sympodium. In the Willows 

 (Fig. 78, d), the end of the branch dies and projects as 

 a dead stump, while in the Hawthorn a spine may result. 

 These features are not difficult to make out in the autumn 

 when the leaves are falling and before the true terminal 

 bud has shrivelled and become displaced. 



Long shoots and dwarf shoots. Most of our forest trees 

 produce two kinds of leafy shoots, but they are not always 

 so well marked as in the Beech and Pine. It is common to 

 find, however, that the buds on a tree do not all develop 

 in the same manner ; some grow rapidly and produce 

 shoots with long internodes, others grow very slowly and 

 have very short internodes. Often the leaves on a dwarf 

 shoot vary in size and form and in the position they ulti- 

 mately assume. Compare the dwarf shoots of Poplar, Birch, 

 Beech, Elm, Hawthorn, Mountain Ash, and Laburnum. 

 We have noticed in many herbaceous perennials that the 

 axis remains short and a rosette of leaves is formed close 

 to the ground. When examining the shoots of trees and 

 shrubs observe how commonly dwarf shoots produce 

 flowers. 



Dormant buds and stool shoots. Adventitious buds. The 

 buds, which arise in the axils of foliage-leaves and scale- 

 leaves, are so numerous that room could not be found 

 for all of them to develop. The food supply, also, is in- 

 sufficient for the purpose. Very frequently those buds arising 

 in the axils of the bud-scales, and in the axils of the lowest 

 foliage-leaves, are very small and do not enlarge in the 

 spring, but lie dormant, although retaining their power 

 of development for a period varying from a few years 



