"P. cactorum" produces one sexually produced survival spore called an oospore, and one asexually produced survival spore called a chlamydospore. Oospores are double-walled and uninucleate during dormancy, but become multinucleate in preparation for germination. In contrast, the chlamydospores have only one resistant wall and are multinucleate at all stages. Chlamydospores are larger than oospores in size, and are only formed under certain environmental triggers. The trigger for preferential formation of chamydospores over oospores can be either large temperature or moisture oscillations.