Pleurotus ostreatus
Pleurotus populinus, the aspen oyster mushroom, is a gilled fungus native to North America. It is found on dead wood of aspen and cottonwood trees (genus "Populus"). Although morphologically similar to "Pleurotus ostreatus" and "Pleurotus pulmonarius", it has been shown to be a distinct species incapable of cross-breeding. "P. populinus" is reported to be edible. Unlike "P. ostreatus", which fruits in the autumn and winter, "P. populinus" fruits in late spring and summer.