Collar Rot on Italian Alder Trees in California Caused by <i>Phytophthora siskiyouensis</i>

Fig. 1. Phytophthora collar rot on Italian alder trees: (D) an isolated bleeding canker on the trunk located approximately 2 m above the ground.



Image from Plant Health Progress article:
Collar Rot on Italian Alder Trees in California Caused by Phytophthora siskiyouensis