A burl is a tree growth in which the grain has grown in a deformed manner. It is commonly found in the form of a rounded outgrowth on a tree trunk or branch that is filled with small knots from dormant buds.

A burl results from a tree undergoing some form of stress. It may be caused by an injury, virus or fungus. Most burls grow beneath the ground, attached to the roots as a type of malignancy that is generally not discovered until the tree dies or falls over. Such burls sometimes appear as groups of bulbous protrusions connected by a system of rope-like roots. Almost all burl wood is covered by bark, even if it is underground. Insect infestation and certain types of mold infestation are the most common causes of this condition.

This shot is of a small section of a redwood burl in macro format. This shot is about one-fourth of the burl, which is approximately 22″ x 9″ x 8″ in its entirety.

EXIF Data

Camera Type: NIKON D3100
Lens: 18.0-55.0 mm f/3.5-5.6
Date Taken: 3/17/13
Aperture: f/11.0
Shutter Speed: 1/125
ISO: 800
Exposure Mode: Manual
Focal Length: 24.0 mm
White Balance: Manual
Metering Mode: Center Weight
Light Source (In Camera): N/A
Flash: Compulsory mode
Light Source (External): Overhead LED
Size: 1 MB
Location: 4361 Custis Avenue, Sacramento, California
Latitude: 38,32.7424N
Longitude: 121,29.8172W
Elevation: 7.70 m