22-Sept The Colourful World of Brittlegills

Traditionally brittlegills are identified in the field by noting their colour, smell, how their cap peels and their taste. As so many are hot and acrid to taste, a small piece is nibbled by experts from the edge of the cap and tasted at the tip of the tongue before then being removed. This unusual method of identification is possible as brittlegills contain no toxins, although it is not recommended with green russulas for fear of confusion with deathcaps. There is a right of passage with young mycologists to taste the hottest russulas which, once tasted, is never forgotten. The hottest and most acrid, and the one you are most encouraged to taste, is R. badia which is almost painful to taste but luckily has been found in Kent but not yet in London.

In a good September you might expect to encounter ten to fifteen different brittlegill species on a foray with five or six being a more usual number. On a bad year not a single specimen will be found. Russulas with red caps are always the ones that catch our eye first especially in beech, oak and Scot’s pine woods. There are seventy of these but less than ten that tend to be seen in London. Generally they tend to be hot or very hot and acrid to taste with some such as R. emetica even irritating the bowel. This species is a fiery red and is often found sitting in moss below pine trees. Two other common red russulas R. mairei (poppy red) and R. betularum (pale pink) are conveniently found under beech and birch respectively.

Russulus with coloured stems are also a little easier to recognise e.g. R. sardonia (rose), R. sanguinea (blood), and R. lepida (carmine). Similarly, the colour of the gills may help e.g. R. pseudointegra (saffron yellow), R. aurea (golden yellow gill edges) and R. luteotacta which has gills which bruise chrome yellow. The colour of caps, stems and gills of most russulas get more variable as they age and many of their colours get easily washed out by rain. However, one or two other more common red russulas are sometimes given away by their particular shade of red e.g. R. velenovskyi (brick), R. vesca (wine) and R. gracillima (ham). Rarely in this group does smell help, but the scent of R. pseudointegra is said to contain elements of menthol, pelargonium and blackberry jam. Kew gardens and Brookwood cemetery are especially good places to look for rarer red russulas. The majority of brittlegills in London tend to be purple, green or various wine colours. One of the most sought after and easiest to recognise is the Charcoal burner R. cyanoxantha.

It is both large and delicious to eat. Unfortunately slugs, squirrels and even deer think so too so it is rarely found either in abundance or totally intact. The caps of charcoal burners are usually a mixture of violet, blue and green, supposedly reflecting all the colours you might see in burning charcoal. If a specimen is found suffused with a lavender colour it may be the closely related R. langei. In this more purple and blue colour group the great beauty is R. caerulea whose cap is the deepest livid purple with a central raised umbo. This is one of the best purples to be seen in any London plant or animal and in this case is set off perfectly with a snow white stem and saffron gills.

Another deep purple russula is R. brunneo violacea and one of the palest is R. violacea, both of which have been recorded in Epping forest.

Brittlegills also produce one of the finest yellows, in the cap of the Yellow Swamp Russala R. claroflava. It is a uniform shiny lemon yellow which in this case is shown off to best effect in the bright green sphagnum moss it generally chooses to grow among in wet birch woods. R. acetolens also can be found under birch but is more of a golden yellow. Two other highly attractive yellow russulas are R. violeipes and R. solaris. The first is a perfect primrose yellow with a violet stipe and the second is more of a lemon yellow but unfortunately smells of vinegar. One last yellow russula worth looking for is R. risigallina which has peach coloured gills and smells of plums and apricots. All these species are not common in London but have been found on Hampstead heath, with the exception of R.solaris which was found nearby in Queens wood.

When it comes to identifying green russulas in the field the usual rule of tasting a little is ignored for fear of confusion with more dangerous species. Luckily the green brittlegills in London can be generally identified by their caps alone. The green-cracking russula R. virescens has an attractive cap with patches of sea green and cream. It is sufficiently well thought of elsewhere in Europe to be gathered in quantity and made into a mushroom extract. R. aeruginea, the grass green russula has no cracks but does have a tendency to develop rusty spots on its cap. Both are not common in London but may still be found in Epping forest, R. virescens in the beech woods and R. aeruginea in the birch woods. Two other green russulas that may also be encountered are R. heterophylla, which is more of a paler yellow green and the green form of the charcoal burner R. cyanoxantha forma cutefracta which is usually given away by its large size.

The black, brown and white russulas tend to be the ugly ducklings of the group. R. nigricans is so black it looks both burnt and almost mummified. Even its gills are solid and set far apart. R. albonigra and R. anthracina look rather more dirty than black. They are not so solid and have far more crowded gills. Two other dirty looking species are R. sororia which smells of Camembert cheese and R. densifolia which, when scratched, turns red then black. With brown russulas it is better to smell and taste them. R. ochroleuca, the Ochre brittlegill, is easily the most common of all the russulas and can be found in nearly all of London’s woods. Although it has no smell and little taste it is easy to recognise by its uninspiring ochre-coloured cap and equally uninspiring grey stem. If that is not enough, the cap cuticle peels off easily almost to its centre. If the brown russula smells oily and rancid it will be the Foetid russula R. foetens and if it smells of bitter almonds R. laurocerasi.

R. farnipes has an elastic cap and R. fellea has a very bitter rather than hot taste. There are several other brown russulas in London so these characters are just pointers as are red stains at the base of the stem in R. pectinatoides and white patches on the cap in R. pseudoaffinis.

Probably only two white russulas are likely to be encountered, R. delica which is exceptionally firm with a strongly rolled edge to its cap and the ivory-coloured R. chlorides which is worth hunting for just to see the strange faint narrow blue-green band separating its gills from its stem.

It is always worth smelling a brittlegill as there is such a wealth of unusual scents, although not everyone has the receptors to enjoy them. A selection of the more interesting ones are R. melliolens (honey), R. amoenolens (Jerusalem artichokes), R. fellea (geranium leaves), R. oderata (boiled sweets), R. graveolens (crab), R. maculata (roses), R. densifolia (old sherry casks), R. cavipes (laudanum), R. fragilis (bubble gum), R. pectinatoides (stewed apple), R. adusta (wine corks) and R. turci (iodoform) but in this last species only at the base of its stem.

It ought perhaps to be added that different authors seem to have very different nasal receptors and occasionally are also prone to exaggeration and hyperbole. When it comes to taste most russulas are either mild, nutty, fruity, hot or acrid but one or two are more interesting e.g. R. rosea tastes of cedarwood pencils and R. albonigra is said to have a cool menthol aftertaste.