Dark Honey Fungus

Dark honey fungus (Armillaria ostoyae). This fungus belongs to the gilled mushrooms (Agaricales). The dark honey fungus is a parasite and occurs on the trunk and root base of deciduous and coniferous trees mainly on sandy soils.

The cap of this honey fungus is cone-shaped and can be 4-20 cm in diameter. The mushroom is brownish in color; from reddish brown to dark brown. The edge of the mushroom is lighter in color and sometimes translucent.

Infestation by the dark honey fungus causes mushrooms to appear on the trunk and treefoam or black-colored sap. This sap and treefoam contain sugars, which insects descend upon. To prevent further attack by the fungus, the tree closes the vessels. The tree sap then oozes through the bark in the form of sap or tree foam. By sealing the vessels, the tree dries out. Often the now-weakened tree is also visited by the Oak jewel beetle, which further accelerates the tree’s decay.

The affected wood rots away, making the tree susceptible to windthrow.

The dark honey fungus resembles the true honeyfungus, but the latter has a yellow edge under the collar of the cap.

The dark honey fungus is not poisonous and is considered edible.