Darkening brittlegill

Overview

Darkening brittlegill, Russula vinosa, is a brittlegill with a wine-red cap that grows with trees in northern European woodland. It is one of the red-capped Russulas, a large genus that contains both edible and inedible species.

The species is recorded in Northern European food sources as a wild mushroom that is cooked before eating. Its name in Swedish, vinkremla, refers to the wine-red colour.

Names and taxonomy

The species was described by Lindblad in 1901 and is placed in the genus Russula, family Russulaceae, order Russulales. The name Russula obscura, from Romell (1906), appears in older use and is recorded as a synonym. The catalogue keeps this as a research name; a current taxonomic review was not carried out for this page.

Common English names include darkening brittlegill and graying olive brittlegill.

Food use

Nordic guides describe the species as mild-tasting and edible. The Swedish guide Svampguiden says a wine-red brittlegill with a mild, sweetish taste is edible, while the inedible brittlegills of this group have a sharply burning taste. It notes that young specimens can occasionally taste somewhat acrid.

The catalogue records the mushroom as a cooked food in Northern Europe, with wild supply. It does not describe a preparation beyond cooking, and it does not establish how widely the species is eaten.

Identification and safety

Wikipedia warns that the red cap is almost impossible to separate by eye from other toxic and inedible red-capped Russulas. Some field guides use a taste test on a small piece as a check, but Wikipedia notes that eating a raw test piece carries some risk, and that experienced foragers usually rely on expert identification.

The catalogue states that darkening is not evidence of edibility across Russula. Edibility here applies to this species only, and it does not transfer to other red-capped brittlegills.

This page is not an identification guide. Do not eat a wild mushroom on the basis of this page. Confirm the identity with an expert before eating any wild fungus.

How to recognise a brittlegill

A mushroom is a brittlegill, a Russula, only when several features line up. The cap is usually brightly coloured. The gills are brittle: they snap when you try to bend them, and the flesh breaks cleanly like chalk instead of tearing into fibres. The stem carries no ring and no cup or sack at its base, and there are no veil remnants on the cap. The gills are attached to the stem, and a spore print is white, cream or dark yellow.

Two checks separate Russula from its look-alikes. Break a gill or cut the flesh: a brittlegill gives no milky juice, while a milkcap (Lactarius or Lactifluus) weeps latex. Then look at the stem. A ring on the stem, a cup or a sack or bulb with torn remnants at its base, or flesh that tears in fibres points away from Russula and towards Amanita, a genus that includes the deadly death cap and many other poisonous species. A mushroom with a ring or a cup at the base is not a Russula, whatever colour its cap is.

Recognising the genus is much easier than naming the species. Cap colour varies widely inside one species, so experts rely on the colour of the spore print, the taste, colour changes in the flesh, how far the cap skin peels, chemical tests and the microscope. A collector who is sure of the genus but not of the species should treat the species as unidentified.

The taste test, and what it cannot tell you

Foragers have long sorted brittlegills by taste. Break off a small piece of cap flesh or gill, chew it for several seconds and spit it out without swallowing; the burn of an acrid species can take half a minute to build. Brittlegills that taste mild are the traditional edibles. Those that taste hot, peppery or acrid, and many bitter ones, are left alone because they irritate the stomach and bowel and can cause vomiting and diarrhoea.

The method works only inside the genus. Use it once the mushroom is positively a Russula, never to decide whether an unknown mushroom is safe: the deadliest mushrooms do not taste unpleasant, and a mild taste says nothing about an Amanita, a Cortinarius or any other family. Within Russula it is a screen for rejecting species, not proof of safety. Some mild species are poor eating, rare species are poorly documented, and a few brittlegills have been linked with poisoning. Cook what you eat, start with a small portion, and identify to species where you can. This record is not a field guide.

Status and open questions

One source lists the species as Vulnerable on a national or regional scale. The IUCN assessment cited by Wikipedia was not confirmed in this research.

Open questions: the sources give no toxicity assessment for the species, no cooking time or method beyond cooking, and no regional comparison of how often it is eaten.