SUMMARYThirty-two species of wood-rotting fungi were found on windthrown ocotillo plants in the Sonoran Desert of southern Arizona. Twenty-seven of these were isolated and their cultural morphology determined. All are homobasidiomycetes exceptXylaria hypoxylon.All caused white rots exceptPanus fulvidus. Cristinia sonoraeandHyphoderma fouquieriaeare described as new species. Standard agar block decay tests with ocotillo wood showed wide variation in decay capabilities of the 27 fungi.