20 ELEMENTARY BOTANY 
CHAPTER LV 
STEMS 
Stems com. VE have already noticed in the seed the young 
pared with stem bearing leaves. This is the most striking 
Roots. characteristic of stems as compared with roots. 
Leaves always come off laterally, and are dissimilar in 
_ appearance to the stem; a root, it is true, does have lateral 
outgrowths, but these always resemble the root and are not 
entirely different in appearance from it, as the leaf is from the 
stem. 
Again, when a stem branches, the branch is formed from the 
outer portion of the stem, not from the inner part as in the 
root. Branches are therefore said to arise exogenously in the 
stem and endogenously in the root. | 
Lastly, the apex of a stem always consists of a bud, whilst 
the apex of the root is occupied by the root-cap. 
TABLE OF COMPARISON. 
STEMS. ROOTS. 
!. Bear leaves. Never bear leaves. 
2. Branches formed exogen- Branches formed endogen- 
ously. ously. 
3. Apex consists of bud. Apex consists of root-cap. — 
Undergrouna ome stems do not come up above ground, but 
Stems distinct these may be distinguished from roots by noting 
renee the following details : 
1, Whether the underground structure consists of nodes and ~ 
internodes. 
2. Whether it bears scales, or anything answering to leaves. 
8. Whether it forms buds, 
