花旗松
Phaeocryptopus gaeumannii is a fungus that infects Douglas fir and causes Swiss needle cast, a yellowing of foliage and reduction in growth. It is endemic in western North American stands of Douglas fir, but was first discovered in Douglas fir trees planted Switzerland. When trees in America were checked, it was found that the fungus was common but apparently caused no disease. However, in the 1980s and 90s the disease became noticeable and problematic.