Brittlegills and Charcoal Burners
Brittlegills form the large genus Russula with around 190 species in the UK. They are easily recognised as a genus but not easy to identify to species. Brittlegills have a distinctive clean shape with a central stem in the centre of a mostly circular cap and gills which are never decurrent (running down the stem a short distance). Only about 20 of 190 UK species can be identified from field characters. The others need at least a spore print and some chemical test.
Brittlegills are mycorrhizal. This means they are associated with particular trees. Always take note of the species of near by trees as his will often help with identification. Some Brittlegills only grow with one type of tree, others are more generalist.
The distinguishing feature of Brittlegills are a white or cream coloured flesh, stem and gills and a coloured cap. The cap colour varies from species to species, think of a colour and there will be a Brittlegill that colour. In a few species the stem is flushed with colour as well, not always the same as the cap colour. In some species the cap is one uniform colour but in many it is a mixture, usually one colour in the centre blending into a completely different colour at the edge. In many species the cap becomes slippery and sticky when wet and often has bits of leaf or twig stuck to it as it dries.
The flesh of Brittlegills is also distinctive. In most mushrooms the cells are long and thin giving them a fibrous texture of some sort. In the Brittlegills, and their relatives the Milk-caps, the cells are spherical and form clumps giving the flesh a crumbly texture. The stems often snap like a piece of chalk as a result.
The crumbly flesh and caps stuck with leaf debris and twigs can be off putting when preparing Brittlegills for cooking. The easiest way to prepare them is remove the larger pieces of debris from the cap and trim the base of the stem. Don’t try to get them spotless. Instead pop them into a pan of hot water or milk and poach them for 5 minutes or so, stirring to dislodge the debris from the mushrooms. Once poached they will be firm and not crumbly and can be drained and used in any dish of your choice. The poaching liquor can be used as stock after straining out the debris.
One useful way to separate the species of Brittlegills is to taste a small piece. Only try the taste test once you have identified the mushroom as a Brittlegill. Some of the poisonous Amanitas, such as The Death Cap can resemble Brittlegills if they have lost their ring and you don’t check for the volva at the base of the stem. Amanitas have fibrous flesh. The tastes of Brittlegills range from mild and fruity or nutty through to bitter, acrid and burning. Try a small piece and spit it out when you have determined the taste.
The spores of Brittlegills are one of the key identifying features. They are very ornate with distinct patterns of warts and bumps for each species. If you have access to a microscope you can identify each species just from their spores (you’ll need a x1000 magnification). The spores also vary in colour from pure white through cream to orange. This can only be seen by taking a spore print and is key to distinguishing some species.
Brittlegills are very popular with animals; mice, squirrels, deer nibble them, slugs and snails graze them and flies and beetles burrow into them. The exposed white flesh is often what draws the attention as the cap is usually coloured to match the fallen leaves around it. When you spot one mushroom, stop, stand still and look carefully around and you will see many more hiding in the leaves.
The Charcoal Burner Russula cyanoxantha
The Charcoal Burner, Russula cyanoxantha, is the one of the best edible Brittlegills. It is easily distinguished from most of the other Brittlegills in the field in having flexible gills. If you run your finger gently across the gills they will bend and not crumble. The other species with this characteristic is Russula langei which is separated from the Charcoal Burner by having a stem flushed with violet. Both are equally edible and delicious.
The cap colour of the Charcoal Burner is problematic with a wide range from green, through blues and purples, to pink. They are never one colour throughout with the centre often slightly brownish. The species name cyanoxantha means blue brown. Russula langei falls in the blue to purple range.
Both Charcoal Burners and Russula langei have a mild fruity taste. Both are mostly found with oak in in summer and autumn.
Common Yellow Russula Russula ochroleuca & Yellow Swamp Russula Russula claroflava
These are two yellow capped Brittlecaps with white stems and white gills. The cap colour of both is uniform bright yellow. The caps become sticky when wet are a often stuck with leaf debris. They are quite fragile mushrooms and crumbly easily when handled. The flesh of the Yellow Swamp Russula slowly bruises grey-black with age.
Both have a mild taste. These two are commonly occur with oak and birch but also pine. The Yellow Swamp Russula is found in damper areas. The are found in autumn and early winter.
There are a few non-edible species with yellow caps. The Velvet Brittlegill R. violeipes is pale yellow with a violet flushed stem. The Sunny Brittlegill R. solaris is pale yellow and is hot tasting, found with beech. The Primrose Brittlegill R. sardonia looks like Common Yellow Russula but is acrid tasting. The Vinegar Brittlegill R. acetolens and related R. ochracea have dark ochre spores and peach coloured gills and smell of vinegar when old. There are also some species with mixed colours in the cap that have some yellow. If the cap is not uniform yellow and has any hint of another colour it is not a Common Yellow Russula or a Yellow Swamp Russula.
Blackening Russula Russula nigricans
The Blackening Russula is one of a group of species that start out white and gradually bruise black with age. They all have firmer flesh than other Brittle-gills or indeed most mushrooms. Because of this they are very slow to rot and can last for a month or more after you first see them. The Piggyback Mushrooms Asterophera spp. only grow on old Blackening Russulas. Although common, the Blackening Russula is not found every year. Four, five even as many as fourteen years may pass with barely any in the woods and then you get a year where they are everywhere in every wood with every beech or oak tree. They are found in early autumn.
The Blackening Russula bruises red which gradually turns black. Some of the other blackening species do not bruise red first. The Blackening Russula is the largest of the group with caps up to 18cm across. They have thick widely spaced gills. Blackening Russula is associated with beech and oak in old woods.
Another common blackening species is the Crowded Brittlegill Russula densifolia which looks and feels like a small Blackening Russula, up to 8cm, but has narrow crowded gills. It is associated with beech and oak in old woods. There are four other species similar to the Crowded Brittlegill which are also edible. They are found with broadleaved trees and occasionally pine.
The Cracked Russula Russula virescens
This is a large matt green Brittlegill distinguished by cracking around the edge of the cap revealing the white flesh beneath to give a mosaic effect. The green colour can fade to yellowish ochre in the sun or with age. It has white stem and crowded cream gills. The taste is mild and nutty. It is found in singly or in small groups with oak, beech and sweet chestnut, often amongst grass.
It could be confused with the green forms of the Charcoal Burner which are also edible.
The Crab Brittlegill Russula xerampelina complex
The is a group of around sixteen species which are distinguished by smelling of crab or shellfish when old or drying. As the term comlex implies they are not easy to identify to species. Most have red or pink caps and several have red or pink flushed stems. As you would expect with sixteen species they can be found with a variety of trees, some associated with pine, some with beech, etc. They are all mild tasting edible species.
The Greasy Grey Brittlegill Russula heterophylla
This is a dull pale greenish-grey species often paler in the centre of the cap. It has a smooth, shiny and slippery cap, especially when wet. It is very fragile and easily crumbles so handle with care. It is found in early autumn with oak, beech and lime.
The Oilslick Brittlegill Russula Ionochlora
This Brittlegill is so named because the cap colour is like the colours of oil on water, a mixture of purple or lilac with a greenish centre. The stem and gills are white. Found with oak.
This Brittlegill is related to the Oilslick Brittlegill and can be confused with it. The cap is a grey-purple colour with a brownish centre. It has tough flesh for a Brittlegill. It is found with broadleaved trees.
The Powdery Brittlegill Russula parazura
The Powdery Brittlegill has a uniform matt pruinose blue cap and white stem and gills. It does not become sticky when wet. The Powdery Brittlegill has a mild fruity taste. It is found with oak, pine, cherry and other fruit trees in early autumn.