Virtual Museum of Canada
Jardin botanique de Montréal 
Centre for Forest Research

A breath of fresh air

Unlike the roots we saw earlier, these ones start underground and grow upward, stretching toward the sky. These aerial roots don't provide any extra support for this bald cypress, nor do they trap any water. So what are they for? Trees that have these pneumatophores, what these strange-looking roots are called, grow in marshy sites where the waterlogged soil contains little oxygen.

Trees don't perform all their gaseous exchanges through the leaves, but through their trunk, branches and roots, as well. These pneumatophores are like lungs for the cypress' root system. They are covered with lenticels (Lens-shaped, biconvex spot on the surface of a plant, which serves as a pore.), which take up oxygen directly from the air, since it's not available to the tree in the soil.

Videoclip Transcription