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

Fig. 3. Sexual and asexual propagules of Phytophthora siskiyouensis: (A) developing oospore of P. siskiyouensis with a paragynous antheridium.



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