Pleurocybella porrigens

Pleurocybella porrigens, commonly known as Angel's Wings, is a delicate, thin-fleshed, fan-shaped white mushroom that fruits in overlapping clusters on decaying conifer wood across temperate forests of North America, Europe, and Asia. Despite its attractive appearance and a long history of being eaten, it is now regarded as a poisonous species that should never be consumed. It has been linked to delayed, sometimes fatal acute encephalopathy, and it is easily mistaken for edible oyster mushrooms (Pleurotus ostreatus).

History

For generations Pleurocybella porrigens — known in Japan as sugihiratake — was foraged and eaten as an edible mushroom. That reputation changed sharply in the autumn of 2004, when an outbreak of acute brain damage in Japan killed at least 17 people who had eaten it. Every person who died had serious pre-existing kidney disease. Subsequent research in mice confirmed that the fungus contains one or more toxins, but their chemical identity has not been determined. The episode reclassified P. porrigens from a traditional edible to a mushroom that should be avoided.

Overview

Pleurocybella porrigens is a saprotrophic fungus that breaks down dead conifer wood, contributing to forest nutrient cycling. It is not edible and is not cultivated for food. Its thin, almost translucent white caps and effectively stemless, laterally attached fruiting bodies grow on coniferous wood, which is the single most useful trait for separating it from the edible oyster mushroom (Pleurotus ostreatus), which grows on hardwoods and has a fruity smell. Because the responsible toxin is unidentified and cannot be neutralised by cooking, and because the risk is especially severe for anyone with reduced kidney function, the only safe practice is to avoid eating this mushroom altogether.