16 Nov 400-year-old oak burr Posted at 15:19h in Blog, Blog by seralvo_administrator 0 Likes Share A burr is a cancer on a plant: in this case it is a “natural” (not artificial) burr on a 400 year-old oak plant, 3.40 metres high, with a diameter of 1,80 metres and weighing 13 tons; it comes from an English park. Share