Entoloma is a very difficult genus and even recognising that you have something rare is not easy for beginners or experienced mycologists. However one group that is easy to identify that we would like any specimen of is the “Big Blue” group. Previously all finds were labelled as Entoloma bloxamii but now it is known that there are at least four species – E. bloxamii s. str., E. atromadidum, E. luteobasis and E. madidum. We would like to work out what we do have in Ireland.
To date, all the NI specimens looked at are E. atromadidum which has a very dark almost black cap. We have had finds of E. madidum confirmed in Donegal and Cork. This can be identified as having a much bluer cap and small spores. There are no Irish records yet of E. bloxamii s. str. or E. luteobasis. E. bloxamii s. str. also has a very blue cap with a lilac tinge but larger spores than E. madidum and E. luteobasis has a browner cap.
Entoloma atromadidum from Galboly on the Garron Point
Entoloma madidum from West Cork
Entoloma luteobasis from northern England
Entoloma bloxamii s. str. Photo by Simon Harding
An unidentified Big Blue (E. bloxamii s. lat.) from the Marlbank from many years ago. Photo by Mark Wright. With those colours, it could have been E. madidum