Shelf mushrooms

When our former neighbor cut down a diseased old maple tree, he had the arborist leave a significant stump. Our neighbor said he did it so he could sit on it and watch the world go by. In twenty years of living next door, we'd never seen him in his front yard except to cut the grass. Turns out we're the ones enjoying the stump. It's become a veritable science lab on our side of the stump. 

A little Google research in the USDA "Field Guide to Common Macrofungi in Eastern Forests and Their Ecosystem Functions" by Michael E. Ostry, Neil A. Anderson and Joseph G. O’Brien identified this as an Artist’s Conk aka Ganoderma applanatum (Fomes applanatus). It is often referred to as a "shelf mushroom" and is not edible. 

It is known by its shelf-like, hard gray-brown zonate upper surface; the white lower surface turns brown when scratched. Its season of fruiting is perennial and its ecosystem function causes a white stem and butt rot of hardwoods. It is not a problem on a dead tree stump like our neighbor's, but is not a good sign when found on an apparently healthy tree. 

Fungal note:  It is the most common perennial wood decay fungus of dead and dying hardwood trees. A single conk can produce 1.25 billion spores each hour for 5-6 months each year. That is an amazing statistic for something that looks so quiet and subtle. 

Comments

[Barbara H.]

Very educational but also a little nerve wracking as a huge old red maple near my patio had a large conk near the bottom - I can't remember I knocked it off - probably not. Glad your neighbor provided such easy access to conk biology.

[Kris P]

I love fungi like this. I've got a half-barrel in a corner of my garden that's been slowly disintegrating for years but I'm loathe to get rid of it because it produces wonderful turkey tail fungi.

[danger garden]

I love these, and now I know not to wish for them on our trees.

[Nell Lancaster]

These made me think of Marcia Donahue's ceramic versions -- safe to place at the base of healthy trees!