Russula cyanoxantha

The Charcoal Burner belongs to the genus Russula, perhaps one of our easiest to recognise fungal groups. The genus is characterised by neat, compact fruit bodies with often a shiny coloured cap and a white stem, which in the UK never has a ring. But it is the crumbly ‘Wensleydale-cheese’ texture of the fruit bodies that is the trademark of this group and which gives the group its name of the Brittlegills. If you draw your finger across the gills on the underside of the cap, they will break up into fragments. In fact, the whole fruit body will crumble into Wensleydale-cheese-like fragments when treated roughly.

The Charcoal Burner often has a wonderful mix of colours in the cap ranging from purple, red, blue, green, to grey and yellow mixed tones. Sometimes a single or a couple of colours will predominate in the cap and a number of varieties or forms of this fungus have been distinguished based on cap colour e.g. Russula cyanoxantha variety flavoviridis – with a greeny-yellow cap.

Although the Brittlegills can usually be readily distinguished as a group, correctly identifying them to individual species can often be very difficult. For the Charcoal Burner, it is actually the absence of the group characteristic – the brittle gills - which is an extremely good field character for distinguishing it from other Russula species. When you draw your finger across the gills of this fungus, they don’t fragment but feel waxy or rubbery or buttery and spring back to their original position once passed. Further identification features are the pure white spore print and the stem is usually white although it can have a purple bloom to it (see group photo). There are two other Russula species that can be mistaken for the Charcoal burner, R. grisea and R. ionochlora, but both these species have cream coloured spores.

There appears to be two explanations for the derivation of the name The Charcoal Burner. Both relate the cap colour to aspects of the charcoal burning industry: one refers to the colours of burning charcoal and the other to the ruddy faces of the charcoal burners themselves. It has been said that the fungus was often collected by the charcoal burners because it could be readily identified with its unique rubbery gills. The taste of the Charcoal Burner is mild and nutty and it is rated to be at place 16 in the “Top 20 Edible Fungi in Britain” list (Legg, 1990).

Occurrence

The fungus is commonly found from June to November although can be found in May in some years.

Habitat

Russula cyanoxantha is a symbiotic ectomycorrhizal fungus, which is commonly found growing in broadleaf woodland containing oak and beech but it also associated with conifers.

Distribution

Russula cyanoxantha is widespread in the UK but judging from the map to the right, is probably under-recorded in Scotland.

Photos by Malcolm Storey, Copyright www.bioimages.org.uk except the group photo which is from Andy Taylor.

By Peggy Ehrlich and Andy Taylor

Russula cyanoxantha

Russula cyanoxantha distribution map

The National Biodiversity Network Gateway records from FRDBI andHBRG datasets are shown on the above map (see terms and conditions at http://data.nbn.org.uk). Data providers and the NBN Trust bear no responsibility for any further analysis or interpretation of the information in the map.