SECTION 4.] 



BUDS. 



27 



Section IV. GROWTH FROM BUDS: BRANCHING. 



45. Most plants increase the amount of their vegetation by branching, 

 that is, by producing lateral shoots. 



46. Roots branch from any part and usually without definite order. 

 Stems normally give rise to branches only at definite points, namely, at the 

 nodes, and there only from the axils of leaves. 



47. Buds (Fig. 72, 73). Every incipient shoot is a Btid (12). A 

 stem continues its growth by its terminal bud; it branches by the forma- 

 tion and development of lateral buds. As normal lateral buds occupy the 

 axils of leaves, they are called axillary buds. As leaves are symmetrically 

 arranged on the stem, the buds in their axils and the branches into which 

 axillary buds grow partake of this symmetry. 

 The most conspicuous buds are the scaly winter- 

 buds of most shrubs and trees of temperate and 

 cold climates ; but the name belongs as well to 

 the forming shoot or branch of any herb. 



48. The Terminal Bud, in the most general 

 sense, may be said to exist in the embryo, as 

 cotyledons, or the cotyledons and plumule, and 

 to crown each successive growth of the simple 

 stem so long as the summit is capable of growth. 

 The whole ascending growth of the Palm, Cy- 

 cas, and the like (such as in Fig. 71) is from 

 a terminal bud. Branches, being repetitions of 

 the main stem and growing in the same way, 

 are also lengthened by terminal buds. Those of 

 Horse-chestnut, Hickory, Maples, and such trees, 

 being the resting buds of winter, are conspicu- 

 ous by their protective covering of scales. 

 These bud-scales, as will hereafter be shown, 

 are themselves a kind of leaves. 



49. Axillary Buds were formed on these 

 annual shoots early in the summer. Occasion- 

 ally they grow the same season into branches ; at least, some of them are 

 pretty sure to do so whenever the growing terminal bud at the end of the 

 shoot is injured or destroyed. Otherwise they may lie dormant until the 

 following spring. In many trees or shrubs these axillary buds do not 

 show themselves until spring ; but if searched for, they may be detected, 

 though of small size, hidden under the bark. Sometimes, although early 



Fig. 72. Shoot of Horse-chestnut, of one year's growth, taken in autumn after the 

 leaves have fallen; showing the large terminal bud and smaller axillary buds. 

 Fia. 73. Similar shoot of Shagbark Hickory, Carya alba. 



