Russula emetica, commonly known as The Sickener, is a basidiomycete mushroom of the genus Russula, one of many species with a predominantly red-coloured cap and white gills and stalk. It gets its common name from its inedibility, as it causes vomiting and diarrhea when consumed. It has an extremely peppery taste, which is said partly to disappear on cooking, along with its toxicity, though eating it is not recommended. Mixing one emetica with otherwise edible red Russula will ruin the whole meal, and it is a common reason some do not pick any red Russula-species.
The sticky cap is 3–10 cm (1¼–4 in) wide and a bright scarlet or cherry red in colour with finely ridged margins. The cuticle is readily peeled from the cap. It is initially convex, then later flat, or depressed. The brittle flesh is white and the taste is very sharp and peppery. The spore print is white, as are the narrowly spaced gills. The stipe is up to 7 cm (3 in) long and 1 cm (½ in) wide, cylindrical and white. The fungus has an unusual fruity smell.
Spores are roughly spherical, with dimensions of 8–10 µm; they are hyaline, and covered with small spines (echinulate).
Distribution and habitatEdit
The Sickener may be found in wet places in coniferous woodlands in Europe, North Africa, Asia and North America, and can be very common. There is some doubt over the extent of its range in North America, as some sightings refer to the related Russula silvicola; initially the name "Russula emetica" was often applied to any red-capped white russula encountered.
As its name implies, the Sickener is inedible, though not as dangerous as once described in older mushroom guides. The symptoms are mainly gastrointestinal in nature: diarrhoea, vomiting and colicky abdominal cramps. The active agent has not been identified but thought to be sesquiterpenes, which have been isolated from the related genus Lactarius and from Russula sardonia.
The bitter taste does disappear on cooking and it is said to be edible, though not recommended. A study in England and southern Scotland found that the Red Squirrel (Sciurus vulgaris) is known to forage for, store and eat the Sickener.