These upward-pointing projections are called Cypress Knees.
They are jealous little things that will punish you for giving too much attention to the sun or moss in the upper boughs, as suddenly you find yourself heaped upon them.

The knees grow from the roots of Cypress trees (as you would guess). Their purpose is not yet understood. It was thought they may bring oxygen to the root system. The still, sepia-colored waters they usually grow near are fairly anaerobic. If you cut them off, though, the tree still thrives. The knees only appear when the tree is near water.

The State Tree of Louisiana, the Bald Cypress populates swamps (“wetlands” for you PC folks) all over the Gulf South, along with the Mayhaws (Cockspur Hawthorns) and red Swamp Maples (Acer rubrum) . This picture was taken at Audubon Park, but a Bald Cypress will grow just fine here in Ohio. In fact, I can show you a nice little grove of giant Bald Cypress hidden very well in Lakeview Cemetery, a 5-minute walk from where I worked:

20090111_cypress_knees_02

not to mention a little poison ivy

Originally posted Jan2009