The first natural hybrids in the genus Phytophthora were described in 1998, and they were the result of hybridization between P. nicotianae and P. cactorum. They were described formally as Phytophthara X pelgrandis in 2009. In 2007 a second type of P. cactorum hybrid species was described, generated by hybridization between P. hedraiandra and P. cactorum; it is described formally here as P. X serendipita sp. nov. The morphological description of P. X pelgrandis was incomplete and here we also add several important diagnostic characters of P. X pelgrandis that were not in its original description. In addition, ITS-SSCP profiles are presented confirming the hybrid identity of both P. pelgrandis and P. X serendipita.