Ok so as Mr.  David Beaulieu iinformed me there are some more cool tree diseases. And it is known under the name of A burl (British bur or burr) according to all mighty wiki.  So as far as i understand its similar to previously described cancer. According to wiki, its cosed by any kind of stress to a tree,.  be it human related humidity related, or most popular is insect infestations. Again according to wiki, burls are always covered with bark, even if they are underground. Ok, but enough words, lets see some pictures (all images taken from wiki here)

burl, image from wiki

burl, image from wiki

burl, image from wiki

burl, image from wiki

burl, image from wiki

burl, image from wiki

burl, image from wiki

burl, image from wiki

So be sure to go here:

flickr

its a flicker search with word burl…. so nice images :)

well thats it for now.

oh oh. some more links:

“art”

wood burls by David Beaulieu

and some famous tree, which is probably not related to burls, but still very nice.

and if you have too much time on your hands be sure to visit my tree models here and here.

dont like english? u can (try) readig it in lithuanian or anny other language here! alternative, has no lithuanian :(