About Exobasidium parvifolii Hotson
Exobasidium parvifolii Hotson is a basidiomycete fungus belonging to the order Exobasidiales. It causes a systemic, perennial polycarpic infection in at least two species of the genus Vaccinium: Vaccinium parvifolium and Vaccinium ovalifolium. Each year, E. parvifolii stimulates its host plants to produce cladomania, which are diseased accessory shoots. Firm, vegetative galls develop in the stems. In spring, the stems produce up to 100 cylindrical excrescences. These fleshy protrusions eventually become covered by a hymenium. By early summer, these structures develop into what are called "shoe-string galls". Exobasidium parvifolii occurs along the northeastern Pacific coasts, ranging from Tlingit territory at its northern extent to Salinan territory at its southern extent. It grows in wet, hypermaritime forested ecosystems where its Vaccinium host plants grow well.
