Abstract
During a survey of Phytophthora diversity in natural ecosystems in Taiwan a swarm of six new species was detected. Multigene phylogeny demonstrated that they belong to ITS Clade 7a with P. alni, P. cambivora, P. europaea, P. fragariaea and P. rubi being their closest relatives. Despite sharing general morphological characters al l six new species differed from related species and from each other by a unique combination of characters including the breeding system, oogonial abortion rates, the proportion of ornamented oogonia, ratios of paragynous and amphyginous antheridia, size of sporangia and oogonia, cardinal temperatures and growth rates.