Editing Burl (section)

==Description==
[[File:Fatburl.jpeg|thumb|right|Large burl on a spruce tree at [[Denali State Park]], Alaska]]

A burl results from a tree undergoing some form of [[stress (biology)|stress]]. It may be caused by a virus, [[Mold (fungus)|fungus]]<ref>{{Cite web |title=What's a "Burl" and Why Is There One on My Tree? |url=https://www.thespruce.com/tree-burl-7153353 |access-date=2024-05-13 |website=The Spruce |language=en}}</ref> or ''[[Agrobacterium tumefaciens]]'' entering the plant through an injury. Most burls grow beneath the ground, attached to the roots as a type of [[Cancer|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 (botany)|bark]], even if it is underground.

In some tree species, burls can grow to great size. The largest, at {{Convert|26|ft|m|0|abbr=on}}, occur in coast redwoods (''[[Sequoia sempervirens]]'') and can engirdle the entire trunk; when moisture is present, these burls can grow new redwood trees. One of the world's largest burls can be found in [[Port McNeill, British Columbia]].<ref>https://www.timescolonist.com/local-news/port-mcneill-moving-beloved-burl-to-new-more-visible-location-8226172</ref>