Climacodon septentrionalis is a species of polypore fungus in the family Meruliaceae. It is a plant pathogen. Originally named Hydnum septentrionale by Elias Magnus Fries in 1821, it was transferred to the genus Climacodon by Peter Karsten in 1881. It is a parasite on the wounds of deciduous trees, especially sugar maple, beech and ash. It can also fruit on standing dead trees. From a distance, Climacodon septentrionalis looks like it is a polypore growing in tiered layers, but its spore-bearing surfaces are actually ‘toothed’ having spines rather than pores. This fungus causes rot of the tree’s heartwood.
It is a parasite on the wounds of deciduous trees, especially sugar maple, beech and ash.