March 2011 – The Local Scoop – A Treebuncle Dropped From The Heavens

A Treebuncle Dropped From The Heavens
It was a rainy day in late October and The Scoop happened upon an amazing discovery on the walk-in commute to work. A treebuncle was sitting forlornly on a storm sewer grate in downtown Toronto; the product of a recent sloughing off a large silver maple. This has got to be the vegetative equivalent of finding a meteorite! We won’t make millions, but its good fodder for a story.
The Scoop settled upon the term “treebuncle” to describe the heavy wooden object with the odoriferous whiff of fungus. We couldn’t call it a “carbuncle” which is a bacterial infection that has nothing to do with cars or trees, though with a hefty weight of about ten pounds, it was lucky it didn’t hit any vehicles that usually park under the tree. Then it would have been a carbonkle.
(Shades of the limb that fell on the Scoopmobile back in September – TLS November issue).
A “tree canker” doesn’t do it justice. It sounds very clinical and doesn’t evoke the work of art that it is. The term “canker” is used to describe a killed area or blister on the bark, a branch or the trunk of an infected tree. The canker-causing fungi commonly invade wounded or injured bark tissues to form a canker. Dozens of species of fungi cause canker disease. It could possibly be the fungus Eutypella parasitica which commonly infects maples. You may have seen it manifested in young stems as the classic ‘cobra head’. Eutypella cankers on maple are often colonized by the decay-causing fungus Oxyporus populinus. Perhaps these fungi were in cahoots with the rain to bring the treebuncle down to earth? But such is the conjecture of arborists who are in the habit of treating tree diseases and pruning limbs. Is the fungus more prevalent in cities where tree pruning is almost a sadistic pleasure? The unkind cuts may lead to more wounding and more entry points and thus, more fun for the fungi.
The old silver maple is host for another much more robust treebuncle (see picture). The Scoop will not be camping out in anticipation of its drop date…but we will keep an eye on it.
 
Treebuncle found in Toronto (2 views: sunnyside up and underside)
 
Treebuncle wound site (in centre of trunk with remaining
treebuncle to the right)
Another treebuncle on silver maple in Toronto
 
Double treebuncle on silver maple Sydneysider treebuncle: A treebuncled tree from downunder.
The “Elephant Man” of the tree world?