96 



INTRODUCTION TO BOTANY 



ax- 



FIG. 79. Accessory 

 buds of box elder 



A, face view of a sin- 

 gle group, with axil- 

 lary bud, ax, between 

 accessory buds ; B, 

 profile view of two 

 opposite groups 



The plumule (fig. 141) is the first terminal bud of the young 

 seedling. Commonly the terminal bud is stronger than any of 



the lateral ones, and makes more rapid 



growth than they do. 



Lateral buds are usually axillary ; that is, 



they arise~ from the axil, or angle formed by 



the leaf with the stem, as shown in figure 



77, ax. Many plants also produce accessory 



buds, that is, 



buds a little 



outside of the 



leaf axil, which 



may either stand 



above the axil- 

 lary bud, as in 



the butternut 



(fig. 78), or on either side of it, 

 as in the box elder (fig. 79). 



Adventitious buds^ are those 

 wKich spring, without any defi- 

 nite order, from roots, stems, or 

 leaves. These are often of great 

 value in propagating plants by 

 means of cuttings or layers. 



91. Bud position and branch- 

 ing ; form of trees. Plants with 

 alternate leaves bear alternate 

 buds, and those with opposite 

 leaves bear opposite buds. If the 

 buds develop into branches, their 

 arrangement will of course fol- 

 low the plan of the leaf arrange- 

 ment. Figures 80 and 81 show 

 the results of one year's growth 

 of twigs from alternate and from opposite buds. Sometimes 

 (fig. 81) the branch is terminated by a flower cluster. In this 



FIG. 80. Alternate branching 



in seedling tree of cultivated 



crab apple 



