Stereum rugosum

Fruiting bodies are perennial, growing on year by year, they are cork-like to woody, when young they are round, 0.2-2 cm in diameter, later they coalesce in irregular almost 50 cm wide fruiting bodies. Hymenium is smooth, rough, pale ochre. When they are wounded while living, they very quickly bleed, later get brown. It grows from spring to winter, as a saprophyte on stumps and on dead parts of woody species, less commonly as a parasite on trunks and branches where it causes necrosis and canker (mainly on oaks). It causes intense rot of the white to yellow colour.