Russula porphyrocephala

Overview

Russula porphyrocephala is a mushroom of the rainforests of Tshopo province in the Democratic Republic of the Congo. It grows in partnership with rainforest trees, as an ectomycorrhizal fungus. Local people in the voucher-backed surveys eat it. Its role as food is recorded in ethnomycological surveys, and the species-specific method of preparation is not established.

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.

Name and taxonomy

The name in the surveys is Russula porphyrocephala Buyck. The catalogue gives no common name for the species and treats the name as a research label rather than a reconciled accepted name.

Food use in Tshopo

The Tshopo edible ectomycorrhizal survey lists the species as a food species, supported by the earlier record of Milenge et al. The wider survey recorded 73 wild mushroom species in use, 68 of them as food. The catalogue marks the record as a food-use observation from voucher-backed interviews.

The surveys record that the species is eaten, but they do not describe a specific method of preparation for it in the sources read here.

Local avoidance

Food use among the Tshopo communities is not uniform. Among six ethnic communities studied near Yangambi and the Yoko reserve, one group avoids Russula. Some Kumu people reject all edible Russula because of their vivid colours, and the same paper records taboos against eating some Russula and Auricularia species. Taboos of this kind limit the use of wild mushrooms in these communities.

Ecology

The catalogue records the species as an ectomycorrhizal rainforest fungus, supplied from the wild.

Safety

The food-use record is an ethnomycological observation. It is not an independent toxicological assessment, and the catalogue states that it does not establish safety. The local taboos show that some communities regard Russula as unsafe or unsuitable. The page gives no edibility verdict, and wild mushrooms should be identified by a qualified person before they are eaten.