Agaricus impudicus (Rea) Pilát

Distribution - Taxonomic History - Etymology - Identification - Culinary Notes - Reference Sources

Agaricus impudicus

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Agaricales

Family: Agaricaceae

Agaricus impudicus is one of the many edible wood mushrooms, but it is far from remarkable for its flavour and so not much sought for by fungi foragers. This attractive species is widespread, but it is only an occasional find in many parts of Britain and Ireland.

Although they occur most often in groups beneath conifers, you may occasionally find these stately mushrooms also in deciduous woods and in mixed woodland.

Distribution

A fairly common woodland mushroom in Britain and Ireland, Agaricus impudicus occurs also in mainland Europe. The specimens shown on this page were photographed in Wales, UK.

Taxonomic history

First described in 1932 by the British mycologist Carleton Rea (1861 - 1946), one of the founders of the British Mycological Society, who gave this species the binomial scientific name Psalliota impudica, this saprobic woodland mushroom was transferred to the genus Agaricus in 1951 by Czech mycologist Albert Pilát (1903 - 1974), whereupon it acquired its currently-accepted scientific name Agaricus impudicus.

Synonyms of Agaricus impudicus include Psalliota impudica Rea,  Psalliota variegata F.H. Møller,  Agaricus variegatus (F.H. Møller) Pilát,  Agaricus variegans F.H. Møller, Psalliota variegata var. koelerionis Bon, and Agaricus koelerionensis (Bon) Bon.

Etymology

The specific epithet impudicus is Latin for 'shameless' or 'immodest'.

Identification guide

Mature cap of Agaricus impudicus

Cap

5 to 10cm across; initially convex, often becoming flat topped as it expands; large scales usually in various shades of dark brown on a pale brown background; whitish flesh either slowly turning very slightly red or unchanging when cut.

Gills of Agaricus impudicus

Gills

Free; crowded; greyish pink, turning brown with age.

Stem

6 to 10cm long and 0.8 to 1.2 cm dia., with a slightly bulbous base; white pendulous ring; surface smooth and white, turning brown with age.

 

Spores

Ellipsoidal to ovoid, smooth, 4-6.7 x 3.7-4.5µm.

Spore print

Chocolate brown.

Odour/taste

Odour strong, unpleasant, reminioscent of radish; taste earthy-mushroomy, unpleasant.

Habitat

Saprobic, usually in groups in conifer forests and mixed woodland.

Season

August to November in Britain and Ireland.

Similar species

Agaricus haemorrhoidarius is very similar, with grey-brown scales and a stouter stem; it occurs under broad-leaved trees, notably oak and beech.

Agaricus augustus, The Prince, is larger and smells of bitter almonds.

Culinary Notes

In Italy, where Agaricus impudicus is a very common mushroom of pine forests, this is considered a good edible species.

Reference Sources

Pat O'Reilly (2011) Fascinated by Fungi; First Nature

The genus Agaricus in Britain, 3rd Edition, self-published, Geoffrey Kibby 2011

BMS List of English Names for Fungi

Funga Nordica: 2nd edition 2012. Edited by Knudsen, H. & Vesterholt, J. ISBN 9788798396130

Dictionary of the Fungi; Paul M. Kirk, Paul F. Cannon, David W. Minter and J. A. Stalpers; CABI, 2008

Taxonomic history and synonym information on these pages is drawn from many sources but in particular from the British Mycological Society's GB Checklist of Fungi and (for basidiomycetes) on Kew's Checklist of the British & Irish Basidiomycota.