Language selection


Sterile conk trunk rot of birch

Sterile conk trunk rot of birch - Advanced decay in paper birch caused by <em>Inonotus obliquus</em>
  • Latin name: Inonotus obliquus (Pers.:Fr.) Pilát
  • French name: Carie blanche spongieuse du bouleau
  • Division: Basidiomycota
  • Class: Aphyllophorales
  • Synonym(s): Polyporus obliquus (Pers.:Fr.) Fr.,
    Poria obliqua (Pers.:Fr.) P. Karst.





Damage, symptoms and biology

The fruiting bodies are composed of black, sterile masses. They are rough and remain on the tree for several years.

Infected trees are severely damaged. The presence of a single sterile conk indicates extensive heartwood decay; 50% to 100% cull is assumed.

Other information

Infection occurs through dead branch stubs, trunk wounds, or through pre-existing cankers (e.g., Nectria) by spores produced by fertile fruiting bodies. Decay characteristics and small sterile conks are similar in appearance to those of Phellinus igniarius.

Canadian Forest Service Publications

Sterile conk trunk rot of birch

Information on host(s)

Main host(s)

White birch, yellow birch

Secondary host(s)

Alders, beeches, cherry birch, grey birch, hickory, ironwood, poplars / aspens / cottonwoods


Page details

Date modified: