Principle species colonised

Many varieties of broadleaves and conifers

Area affected

Initially in roots, which are colonised and sometimes killed by parasitic action. The fungus then spreads up into the stem; more in some host species than others.

Type of decay.

A stringy-textured white pocket rot with selective delignification, which causes delamination and rigidity loss in the early stages. Later, stem hollowing may result from cellulose breakdown.

Fruit body and other fungal structures

Thin brackets or occasionally creating a layer (resupinate) on the surface of the host. The brackets are brown with concentric zones and a white expanding edge on the upper sides. They are thin, robust, and leathery, and they are typically 50 to 100 mm broad (occasionally 300 mm or more).
They often absorb fallen twigs or pine needles and originate mostly in the spaces between the buttresses or in soil holes surrounding the roots. The very tiny pores are found on a light, frequently pink-flushed surface.

Seasonality and perseverance When circumstances are favourable, the brackets increase. Although they are perennials, really cold temperatures can destroy them.

Impact / Effect / Significance

Standing trees may die from root killing in some host species, particularly pines. Other species may experience ductile failure due to a loss of stiffness, however this can lead to compensatory growth. The value of timber is frequently severely lost.