Paxillus involutus

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Paxillus involutus
Scientific classification
Kingdom: Fungi Phylum: Basidiomycota Class: Basidiomycetes Order: Boletales Family: Paxillaceae Genus: Paxillus Species: P. involutus
Binomial name
Paxillus involutus (Batsch ex Fr.) Fr.

The common or brown roll-rim, Paxillus involutus, also known as the poison pax, is a mushroom previously thought to be edible with some unusual recently-discovered poisonous properties. It can cause a haemolysis which can be fatal. It often grows near edible mushrooms as well which makes it harder to identify by amateur mushroomers.

Contents 1 Identification 2 Habitat 3 Toxicity 4 References 5 External links

[edit] Identification

The cap, initially convex then more funnel-shaped with a depressed centre and rolled rim (hence the common name), is brown in colour and 4-10 cm wide. The narrow brownish yellow gills are decurrent and forked, darkening when bruised. It has a mild odour and taste. The spore print is brown. The stipe can be crooked and brownish or greyish yellow in colour.

[edit] Habitat

The brown roll-rim can found growing on lawns and old meadows, as well as deciduous and coniferous woodlands in Europe and North America in summer and autumn. It is an uncommon mushroom.

[edit] Toxicity

Previously deemed edible after cooking (it can cause gastric upset when raw), Flammer in 1980 discovered an antigen within the mushroom which stimulates an autoimmune reaction causing the body's immune cells to consider its own red blood cells as foreign and attack them. This results in dangerous haemolysis, which has been fatal.^[1]

The use of corticosteroids may be useful in treatment.^[2]

[edit] References

[edit] External links

Mushrooms Expert on the brown roll-rim