Large polypore fungus (Fomitopsis pinicola). Growing on a conifer trunk in an Alsace forest, the red banded polypore, or conk, is an old specimen over 30 cm wide. It is a perennial with a new layer of pores produced each year below the old pores and over years it can take on strange forms. Classified as brown rot, it infests the tree's heartwood which makes it unusable for timber or wood pulp. It is found on living and dead trees. It is common in Europe and Asia, although rare in the UK.