Sericeomollis brown cubical butt

• French disease name: Carie brune cubique du pied à Postia sericeomollis
• Pathogen name: Postia sericeomollis (Romell) Jülich
• Class: Aphyllophorales
• Partial list of synonyms:
  • Oligoporus sericeomollis-2 (Romwell) Pouzar
  • Polyporus sericeomollis-2 Romwell
  • Poria asiatica-2 (Pilàt) Overh.
  • Poria sericeomollis-2 (Romwell) Egeland
  • Tyromyces sericeomollis-2 (Romwell) Bondartsev & Singer

Distribution

Canada

Damage, symptoms and biology

The annual fruiting bodies are tablet- or hoof-shaped, with a white hairy upper surface that turns brown. The underside is white, turning cream-coloured or yellow. This fungus colonizes and decays wood already infected by other fungi. It is often found on stumps or trunks of downed trees.

This decay is very common in the butt logs of western red cedar, resulting in significant volume losses in both interior and coastal trees. Brown cubical rot symptoms are commonly found in cedar lumber but the decay is not known to develop further in wood in service.

Other information

Cedar pocket rot is an important butt and trunk decay of western red cedar, ranking second to Phellinus pini as the most common decay in that species. Postia sericeomollis could be confused with Phaeolus schweinitzii. Decay in the former, however, usually forms in pockets or rings of decay, whereas P. schweinitzii usually forms a single column of decay in the centre of the stem. This distinction may be less clear in the stump than higher in the stem. In addition, P. schweinitzii is rarely found in western red cedar.

Canadian Forest Service Publications

Sericeomollis brown cubical butt

Information on host(s)

Main host(s)

Balsam fir, birch, cherries / plums, Engelmann spruce, grand fir, jack pine, juniper, lodgepole pine, Nootka false cypress, pines, Rocky Mountain Douglas-fir, shore pine, Sitka spruce, subalpine fir, western hemlock, western larch, white spruce