Editing Burl (section)

{{short description|Deformed tree outgrowth}}
{{other uses}}
{{More footnotes|date=June 2011}}

[[File:Growth on tree trunk - geograph.org.uk - 724687.jpg|right|thumb|200px|Burrs on a tree trunk in [[Norfolk]], England]]

A '''burl''' (American English) or '''burr''' (British English) is a tree growth in which the [[wood grain|grain]] has grown in a [[Deformity|deformed]] manner. It is commonly found in the form of a rounded outgrowth on a tree [[Trunk (botany)|trunk]] or [[branch]] that is filled with small [[Knothole|knots]] from dormant buds. Burl formation is typically a result of some form of stress such as an injury or a viral or fungal infection. More scientifically, a burl is “the result of [[hyperplasia]], a greatly abnormal proliferation of [[xylem]] production by the [[vascular cambium]]”.<ref> Smith, Kevin T. 2012. The biology of burls. Bark. Issue 3(2012): 6. [Published by Massachusetts Tree Wardens and Foresters Association]. https://research.fs.usda.gov/treesearch/42292 </ref><ref>https://extension.unh.edu/blog/2022/01/mystery-tree-burls</ref>

Burls yield a very peculiar and highly figured wood sought after in woodworking, and some items may reach high prices on the wood market. [[Poaching]] of burl specimens and damaging the trees in the process poses a problem in some areas.