Neofusicoccum arbuti

Description: 

Identification: Sunken cankers with callused margins on the main stem and branches. The fungus is spread by conidia and produces christmas tree shaped conidiophores. 

Hosts: Arbutus menziesii (Pacific Madrone) 

Distribution: This pathogen has a preference for milder climates and is thus only present in the northernly range of madrone trees. Arbutus menziesii’s native range is from coastal regions in Southern BC all the way down to the middle of the coast of California. 

General Information:

References:

1. http://www.puyallup.wsu.edu/ppo/madrone/diseases/dieback.htm