''Phellinus weirii'' is a plant pathogen causing

laminated root rot Laminated root rot also known as yellow ring rot is caused by the fungal pathogen ''Phellinus weirii''. Laminated root rot is one of the most damaging root disease amongst conifers in northwestern America and true firs, Douglas fir, Mountain hem ...

in certain conifers, typically

Douglas-fir The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three va ...

and

western redcedar ''Thuja plicata'' is an evergreen coniferous tree in the cypress family Cupressaceae, native to western North America. Its common name is western redcedar (western red cedar in the UK), and it is also called Pacific redcedar, giant arborvitae, w ...

. It is widespread in the Douglas-fir growing regions of

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

and

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...

Overview

Symptoms of fungal infection are readily recognized when timber is cut because a brown stain will appear on the butt cut. In early stages it will be just a spot in the heart wood, but as the disease advances it will extend most of the way around the heart wood, and in extreme cases may result in a hollow stump. Usually it is not observed more than a few feet above ground level. Losses due to the fungus are estimated at 4.4 million m³ (157 million ft³) of timber in the Northwestern United States and in British Columbia. Reduced growth rate is an attribute of tree infection. Particular attention is invited to the growth ring patterns visible in the images attached. Image:Laminatedroot1.jpg, Moderately advanced infection Image:Laminatedroot2.jpg, Close up of ''Phellinus weirii'' infection at Apiary, Oregon File:Phellinus weirii rot.jpg, Hollow log at stump level---An extreme case of infection File:Phellinus weirii on a log.jpg, View of long butt showing reduced rot a few feet up from the stump

References

Fungal conifer pathogens and diseases weirii Fungi described in 1914 Fungi of North America Taxa named by William Alphonso Murrill {{Agaricomycetes-stub