Re: How do trees drink water?

Hi Bekka -

Trees use a process called transpiration to obtain water from the ground, through the roots, up the trunk and branches, and into the leaves. Evaporation drives the flow of water - just as though you left a bowl of water out, and the water disappeared over time. Water evaporates from small holes in the tree's leaves. Scientists refer to these holes as stomata, the latin word for "hole." Water in the branches replaces the water lost from the leaves.. which pulls water along the trunk, and ultimately from the roots. The tree trunk has specialized "vascular" areas for transporting the water and nutrients (called phloem , pronounced "flow-em").

Try the experiment, "Coloring Plant Transpiration" in the Edible/Inedible Experiments Archive to see transpiration in action. By using food dyes you can follow the progress of water along a flower's stem and into the petals. I find that blue works the best (for both scientific and floral effect..). If you then cut the stem in cross-section, the highly colored areas represent the vascular bundles of phloem. You can learn more about plants by trying some of the botany links in the Try the links in the MadSci Library for more information on Botany.

Have fun.. a blue flower can never be a bad thing.

Lynn Bry, MadSci Admin