CHAPTER X 



xt 



■d 



BUDS; GROWTH OF STEMS; PRUNING; PROPA- 

 GATION BY STEMS 



Buds 



Nature of Buds. — Buds contain a partially developed portion 

 of a stem with leaves and also flowers, when present, in an em- 

 bryonic state. A close study of buds, hke those of fruit trees, 

 shows that the stem portion contained is 

 very short and that the leaves and flowers, 

 although they may be seen with a micro- 

 scope of low power or often with the naked 

 eye, are very rudimentary. Buds are often 

 1-^ defined as undeveloped shoots. The most 

 l-c important thing about a bud is that it con- 

 tains the meristematic tissues upon which 

 growth in length (primary growth) and the 

 formation of new leaves and flowers depend. 

 For this reason, when the bud on the end of 

 Fig. 182. — Length- ^ branch is removed, the branch can grow no 

 ■wise section through a . , ,, ... . -, /n- -,o/n\ 



bud of the Ba^wood. ^ore m length at that pomt. {Fig. 182.) 



a, outer scales; h, mer- Buds are common to all plants, but they 

 istematic tip; c, un- are most noticeable in perennials, such as 

 developed leaves and ^^^^ which have dormant periods occurring 

 flowers; a, end of twig , . , , . , . , , 



where the formation of durmg the wmter season m temperate re- 

 stem tissues, such as gions or during dry seasons in warm coun- 

 epidermis, cortex, vas- tries. The buds of these plants are known 

 cular cylinder and pith ^^ ^^^^ ^^^^ ^^^ ^^^ ^^^^^ covered with 

 termmated last season. , ^ ■ , , • • ,• 



After Charlotte King, scales which protect the inner portions from 



drying and other destructive agencies. The 

 scales overlap, forming a covering of more than one layer, and 

 are often made more protective by becoming hairy or waxy. Bud 

 scales are closely related to leaves and, in most cases, are simply 

 modified leaves. Sometimes, however, they are modified stipules 

 which are leaf appendages. 



204 



