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

Fig. 3. Sexual and asexual propagules of Phytophthora siskiyouensis: (B) ellipsoid, semi-papillate sporangia, including one sporangium releasing zoospores (inset).



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