Greencracked brittlegill

Overview

Greencracked brittlegill is a tree-associated wild mushroom of Europe. The catalogue records it as a popular cooked mushroom, and reports broader historical Asian records that include distinct species. Its cap is the feature that gives it its name: a green surface that cracks into a mosaic of patches.

Edibility is not settled across the sources. Some field guides list it as edible, and some list the closely related green russulas differently. Because the genus contains toxic species, the popularity of the cooked dish is not a guarantee for any collection.

Description

Field guides describe the cap as dull olive-green with patches, cushion-shaped when young and later convex or vase-shaped. The gills are cream-coloured, the flesh is thick and brittle, and the spore print is white. The white stipe can reach about 8 centimetres tall and turns brownish with age.

Ecology

Russula virescens is a mycorrhizal fungus that grows with trees, and the catalogue records its supply as wild. No cultivation is recorded.

Food use

The catalogue calls it a popular cooked mushroom. One field-guide summary lists it as edible, and another describes its flavour as good. A third source on the wider green-russula group says it is recorded as edible in some guides and inedible in others, and that source is about a related species, so it does not settle the question for this one.

Some sources describe a practical taste test: a mild, pleasant taste is treated as a sign of edibility, and a hot or acrid taste as a sign of a poisonous Russula. That is a general rule for the genus and does not replace identification.

Identification and safety

Russula are hard to separate in the field, and many green species look alike. North American material is thought to contain more than one species. The Asian material in the catalogue includes distinct species, and green caps can create dangerous confusion. Confirm identification by spore print and microscopy with a qualified mycologist or a reliable regional authority before eating.

Do not use this page to identify or eat wild fungi.

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.