bald cypress

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A deciduous coniferous tree (Taxodium distichum) native to swamps and river floodplains chiefly of the southeast United States, having flat, needle-like leaves, roundish cones, and sometimes aerial root knees.
• noun The decay-resistant wood of this tree, used in construction and boat building.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun smaller than and often included in the closely related Taxodium distichum
• noun common cypress of southeastern United States having trunk expanded at base; found in coastal swamps and flooding river bottoms