
CHAPTER V 
THE STEM 
The chief function of the stem is to support the leaves and 
reproductive organs in such a manner that they can advan- 
tageously carry on their several functions. When we analyze 
this function of the stem, we find that several aspects must be 
considered. ‘These can be grouped under attachment, position, 
and increase in number of leaves and reproductive organs. 
Attachment. The stem furnishes any organ which it bears with 
a place of attachment, and thus enables that organ to maintain 
its position. 
Position. In most cases, stems serve to distribute the leaves 
in such a manner that they do not shade each other to any great 
extent. Insect-pollinated flowers are usually in such a position 
that they are readily visible to the pollinating agents, while 
wind-pollinated flowers are so exposed that the pollen may be 
carried by wind from one flower to another. Stems support most 
fruits in such a way that they may be readily distributed by 
disseminating agents. 
Increase in number. Many stems serve greatly to increase the 
number of leaves and reproductive organs that are produced by 
the plant. The stem, by increasing the number of leaves that the 
plant bears, enables the plant to produce more food and, con- 
sequently, a greater number of seeds. 
Incidental functions. Besides the main function of support the 
stem has two important incidental functions: namely, to conduct 
water from the roots to the leaves and reproductive structures, 
and to carry food from the leaves to other parts of the plant. 
It is evident that if leaves and flowers were attached directly 
to the roots, there would be no need and no possibility for any 
other organ to conduct materials between roots and leaves. 
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