9 6 
THE GARDEN OF THE WORLD 
neath the pond, for it must have nitrogen and 
other minerals which only the soil can supply. 
The biggest and best water lilies are found in 
ponds where the soil underneath is rich and 
black. If the pond has a sandy bottom, the 
lilies will not do so well there. 
Water plants have one advantage over land 
plants; they do not need strong woody stems 
to support them. They can save the energy 
other plants use in growing strong stems for 
building big leaves to make food and for beau¬ 
tiful flowers. They do not need long tubes in 
their stems and leaves to carry water because 
the water is near to all parts of the plant. 
Some water plants like bulrushes and cat-tails 
have strong stems. They are then able to grow 
on land as well as in the water. This is very 
useful to them in case their pond or stream 
should dry up. 
Some other water plants grow completely 
under water. They do not need strong stems, 
but they are at a disadvantage when making 
food, for the sunlight has to pass through the 
