Phellinus sulphurascens and the closely related P. weirii in North America

Monokaryotic isolates of Phellinus sulphurascens, a fungus originally described from the Primorsk Territory, Russia, are compatible with monokaryotic isolates of, what has been called in North America, the Douglas-fir form of P. weirii. Phellinus weirii, originally described from Idaho as a root and stem decay fungus of western redcedar, is not compatible with monokaryotic isolates of P. sulphurascens or the Douglas-fir form of P. weirii. Differences between P. sulphurascens and P. weirii are noted. Observations on the behavior of P. weirii (cedar form) on western redcedar are also reported. Both fungi are referred to the genus Inonotus, and the new combination Inonotus sulphurascens is proposed.