20 - ELEMENTARY BOTANY 
CHAPTER IV 
STEMS 
Seneca ane 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 
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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. 
Badeneound Some stems do not come Up above ground, but 
Stems distinct these may be distinguished from roots by noting 
from Roots. the following details : 
1. Whether the underground structure consists of nodes and 
internodes. 
2. Whether it bears scales, or anything answering to leaves, 
&. Whether it forms buds. 
