Ash

Arbuscular mycorrhiza and spring morels

In her "Key to the Fungi of Ukraine," M. Ya. Zerova explains that the ash, like the maple, does not form ectomycorrhiza with cap mushrooms. Its root system enters into endomycorrhiza (arbuscular mycorrhiza) with microscopic soil fungi that produce no fruiting bodies.

That's why under an ash you will never find:

- Boletes (porcini, birch boletes, slippery jacks)

- Chanterelles or hedgehog mushrooms

- Brittlegills and milk caps

- Truffles or death caps

However, in "Mushrooms Demystified," David Arora points to one remarkable exception. Although the ash has no autumn mycorrhizal partners, the soil around it (often rich in calcium and humus) is one of the favorite growing spots of spring mushrooms — the morels (Morchella). The common morel and the black morel very often fruit in April–May precisely under old ashes and elms. This bond isn't mycorrhizal in the classic sense (morels are often soil saprotrophs), but their ecological tie to the ash is very strong.

Ash as a substrate for saprotrophs

Ash wood is strong and springy, but once it dies it is quickly colonized by specialized wood-decaying fungi:

- Dryad's saddle (Polyporus squamosus): As on other broadleaf trees, this mushroom can develop on a living ash through wounds.

- Oyster mushroom (Pleurotus ostreatus): Fallen ashes in damp places are often covered with generous colonies of oyster mushrooms.

- Shaggy bracket (Inonotus hispidus): A large, hairy, brown parasitic fungus that often destroys living ashes.