365 Urban Species. #244: Ash Tree Bolete

[urbpan]

Photos by cottonmanifesto. Location: Parkway Road, Brookline. The mushroom on the center right has been turned upside-down, showing the spore-producing underside.

Urban species #244: Ash tree bolete Gyrodon merulioides

A bolete is a mushroom that has a porous spore-bearing surface, rather than the more familiar "gills" (for an example of a gilled mushroom see the amethyst deceiver). The pores of the ash tree bolete are uniquely and rather beautifully shaped. The top of the mushroom looks rather like a carelessly poured pancake, irregularly kidney-shaped, resting on an off-center stalk. The fungus that produces this mushroom always grows in association with the roots of ash trees including green ash, Fraxinus pennsylvanica, a very common urban tree. According to one study* this fungus is dependent on an aphid which feeds on the ash tree, providing nourishment for the fungus as a by-product. Despite this very specific collection of organisms that need to be present for this mushroom to appear, it is not uncommon. Ash tree bolete is edible, despite the fact that it violates an old mushroomer's rule: when bruised, it's flesh stains blue; supposedly an indication that it is poisonous. However, it is not a very well sought-after mushroom, except by slugs and other invertebrate grazers.



* The connection between Gyrodon merulioides and wooly ash aphids was apparently made in a 1987 paper by M.C. Brundrett and B. Kendrick, in the journal Symbiosis. I have found numerous sources using this paper as a reference, but this seems to be the only study describing this relationship. I have not read this paper.

Comments

[mmsword.livejournal.com]

About the Blue Staining: The logic behind avoiding blue staining Boletes is that there are a good number of hard to distinguish boletes that stain blue and it would be better off to avoid the whole group, along with red pored boletes, then to risk getting confused with a look alike. The same logic goes behind avoiding all Amanitas, though the stakes are quite a bit higher in that case.

[whatisbiscuits.livejournal.com]

beautiful! I find fungi fascinating.

[shadefell.livejournal.com]

On my walk home from work I pass a tree stump that has a fungus very similiar to the one featured here. I'd been wondering what it was (and I never used to wonder about fungus until I started reading this blog), and here I have an answer!

[serendipityone.livejournal.com]

I have posted a photo in the garden and organic_garden communities to find out about this very large mushroom growing in my back yard. Here is one of the post http://community.livejournal.com/organic_garden/83873.html.
I would really like to find out that it's not poisonous and if not, if it can be eaten? Thanks for any help.