Where do burrs come from?

[Anonymous]

Having just used some burr elm, I wondered when I was lookng at it why its so different from plain elm. How are burrs made? Is it a seperate type or does something weird happen to the wood (like spalting changes beech or birch?)
Cheers a (curious) jonathan

 

[cd]

Hi Mr S
I recently turned a bowl for a friend from an oak burr he asked me the same question. The best I could do was a quick google search for him and came up with these.
http://www.redwood.national-park.com/info.htm#bur
and
http://www.newton.dep.anl.gov/natbltn/600-699/nb629.htm
I think if your serching yourself try "burls" which is what I believe the American term for them is.

HTH

cd

 

[CHJ]

I believe a lot of Burrs on English trees are formed when the tree, for whatever reason (damage, infection, genetic defect etc.) persistently sprouts new bud growth which fails to emerge beyond the bark.

 

[garywayne]

Chas is right. I was told by my old tutor that burr is basically a cancer in trees, a load of branches that don't grow proper.

If you look around at trees, you will on occasions see trees with a bulbous trunk. That is the cancer, or burr.

I hope that makes sense, and is of some help.