This tree burl on an oak is one I check on regularly to see if the tree is still there. I call it the Sasquatch burl and have visited it for over 20 years.

Burls are formed when a pathogen attacks a tree or an insect burrows in and lays its eggs inside. Cell division is accelerated and the tree creates new tissue to isolate the injury and protect itself. These are also referred to as Galls or Boles. Burls are called Burrs in Britain.

Burls are often used to create unique furniture and decorative items due to their grain.

#treeburls #burls #galls #burrs #boles

"California’s redwood trees are a national treasure and a living witness to our past. The largest of California’s redwoods grow in excess of two hundred and fifty feet tall and are capable of living for millennia. In recent years, an alarming number of old-growth trees residing in Redwood National Park have been shorn of the gnarled protrusions that grow on their trunks, called burls. Essential to the tree’s reproduction process, these burls are illegally cut by poachers who seek to sell the distinctive wood on the black market for use in fine woodworking. Concerned over the welfare of the iconic old-growth trees, photographers Kirk Crippens and Gretchen LeMaistre work with park rangers to access and photograph each damaged tree for their series, Live Burls. Working with a traditional 8x10 inch analog view camera, the artists produce breathtaking images that recall the majestic beauty of the ancient trees while drawing attention to the environmental injustice at hand. See "Live Burls" by #KirkCrippens and #GretchenLeMaistre , on display, pre-security in Terminal 1. http://bit.ly/2x8ZtST" This was posted to our Instagram account on September 17, 2018 – https://millsfield.sfomuseum.org/instagram/1729357665/

"California’s redwood trees are a national treasure and a living witness to our past. The largest of California’s redwoods grow in excess of two hundred and fifty feet tall and are capable of living for millennia. In recent years, an alarming number of old-growth trees residing in Redwood National Park have been shorn of the gnarled protrusions that grow on their trunks, called burls. Essential to the tree’s reproduction process, these burls are illegally cut by poachers who seek to sell the distinctive wood on the black market for use in fine woodworking. Concerned over the welfare of the iconic old-growth trees, photographers Kirk Crippens and Gretchen LeMaistre work with park rangers to access and photograph each damaged tree for their series, Live Burls. Working with a traditional 8x10 inch analog view camera, the artists produce breathtaking images that recall the majestic beauty of the ancient trees while drawing attention to the environmental injustice at hand. See "Live Burls" by #KirkCrippens and #GretchenLeMaistre , on display, pre-security in Terminal 1. http://bit.ly/2x8ZtST" This was posted to our Instagram account on September 17, 2018 – https://millsfield.sfomuseum.org/instagram/1729357665/