Noninfectious Disorders
FIELD GUIDE TO INSECTS AND DISEASES OF ARIZONA AND NEW MEXICO FORESTS
Burls

Burls are large woody, more or less hemispheric, swellings on the main stems of trees. Although some stem swellings are the result of pathogens, often the cause of burls is unknown. Burls may often bear many buds or sprouts.

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Figure 295. Figure 295. The cause of burls is often unknown.