AERIAL ROOTS FROM OLD TREE WOUND'
WILLIAM A. NESBITT
(WITH ONE FIGURE)
Recently, a lnorthern red oak tree was found on the Bent Creek Experimental Forest, Buncombe County, North Carolina, with an unusual and
interesting group of aerial roots originating from the callused area surrounding an old wound.
This tree, shown in the accompanying photograph, is about 100 feet high,
has approximately 3 log lengths and is 33.5 inches in diameter at 4.5 feet
above the ground. It is an overmature or decadent tree, with a rather flat
top, two or three large dead limbs, and a large "conk" on the bole about
40 feet above ground. Otherwise it is apparently in good health.- According to ring counts on the callused area surrounding the wound, 11 years have
elapsed since some undetermined cause killed approximately one-third of the
eircumference, from the ground line to an average height of 7 feet. Most
of the bark over the wounded or dead area was intact when the tree was
discovered a short time ago. Approximately two inches of the sapwood has
decayed and is now in a dry powdery-rot condition, with hundreds of small
worm holes extending into the heartwood. The area surrounding the wound
has callused in the usual manner. The live portion directly above the
wound, and at one point midway up on the side of the callused area, has
sent out groups of rope-like growths extending to the ground and forming
fibrous roots. There are three separate such growths, approximately one
inch in diameter, reaching the ground, with several smaller ones extending
varying distances down through the rotted sapwood under the bark. A
portion of the fibrous roots from one of the strands is shown lying on top
of the hammer in the photograph on page 690. These rope-like aerial
roots are provided with a bark covering similar to ordinary roots, and are
independent of the parent tree, except at their point of origin.
APPALACHIAN FOREST EXPERIMENT STATION
ASHEVILLE, NORTH CAROLINA
Contribution from the Appalachian Forest Experiment Station.
689
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PLANT PHYSIOLOGY
FIG. 1. Red oak tree with aerial roots which have arisen from the callus of a wound.
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