Hericium Butt Rot, Hericium erinaceus (Pers.:Fr.) Murr.

Leininger, T.D; Solomon, J.D.; Wilson, A. Dan; Schiff, N.M. 1999. A Guide to Major Insects, Diseases, Air Pollution Injury, and Chemical Injury of Sycamore. Gen. Tech. Rep. SRS-28. Asheville, NC: USDA Forest Service, Southern Research Station. 44 p.

Importance.-Hericium butt rot most commonly occurs in oaks, but it is also found in many other hardwoods throughout the Eastern United States, including sycamore, beech, birch, hickories, maples, and persimmon trees.

Identifying the Disease.-The fungus causes a white, soft, and spongy rot of heartwood in the butt and lower bole of the tree. Decayed wood eventually disintegrates leaving a cavity in the center of the tree. Because external cankers are not formed in the outer bark, no evidence of the disease is visible except for seasonal fruiting bodies.

Figure 34. - Fruiting bodies of Hericium erinaceus on a fire-scarred sycamore.

Identifying the Fungus.-Large (up to 30 cm wide), soft, white, and fleshy fruiting bodies form on the boles of living trees, singly or in clusters, during the rainy autumn and winter months. They are initially round and smooth on all surfaces, but develop long, pendant “teeth” on the lower surface and gradually turn yellowish with age (fig. 34).

Biology-Spores of the fungus, released from fruiting bodies on infected trees, germinate and infect trees through fire or logging scars, stem cracks, and branch stubs near tree bases. Fruiting bodies form after extensive decay of the heartwood has occurred.

Control.-Hericium butt rot is best controlled when thinning stands by preventing wounds and broken branches on residual trees caused by logging equipment, skidding logs, and falling trees. Preventing fire scars is also suggested.