Contribution to the knowledge of Pythium species of Iran.
The 35 isolates studied included the following new records for Iran: P. coloratum, P. intermedium, P. oligandrum and P. vexans which are described and illustrated. The most frequent isolates were the thermophilic spp. such as P. aphanidermatum and P. ultimum. Previously reported spp. are listed with their hosts and a host-pathogen table is included.