Maple

Arbuscular mycorrhiza and the absence of ectomycorrhiza

From a mycological point of view, the maple (Acer) is a classic example of a tree that does not support ectomycorrhiza. M. Ya. Zerova explains that ectomycorrhiza (where the mycelium wraps the rootlet from the outside and produces large fruiting bodies) is typical of oaks, pines and birches. The maple, by contrast, forms endomycorrhiza (arbuscular mycorrhiza).

In "Mushrooms Demystified," David Arora notes that arbuscular mycorrhiza is formed by microscopic fungi of the division Glomeromycota. Their structures penetrate deep inside the cells of the maple's roots, but they never produce macroscopic fruiting bodies (caps with stems) above ground.

That's why in a pure maple wood (with no oak, hornbeam or pine mixed in) it is absolutely impossible to find:

- Boletes (porcini, slippery jacks, birch boletes, Suillellus boletes)

- Chanterelles and hedgehog mushrooms

- Brittlegills and milk caps

- Truffles

- Deadly dangerous death caps and amanitas

Saprotrophic mushrooms on maple

Although there are no mycorrhizal mushrooms in the soil, maple wood is an excellent substrate for organisms that feed on dead organic matter. Roger Phillips lists the main saprotrophs and parasites associated with the maple:

1. Dryad's saddle (Polyporus squamosus): As on other park trees, this parasitic mushroom — edible when young — often gets into the trunks of living maples through wounds and broken-off branches.

2. Velvet shank (Flammulina velutipes): In autumn and winter, old maple stumps and fallen trunks are often covered with bright orange clusters of Flammulina.

3. Oyster mushroom (Pleurotus ostreatus): Often uses fallen maple wood to grow.

4. Coral fungi and specialized bracket fungi: Small wood-decaying fungi such as Nectria or Stereum often develop on dead maple branches.