sometimes described in older mushroom guides. The symptoms are mainly gastrointestinal in nature: nausea, diarrhoea, vomiting, and colicky abdominal cramps. These symptoms typically begin half an hour to three hours after ingestion of the mushroom, and usually subside spontaneously, or shortly after the ingested material has been expelled from the intestinal tract. The active agents have not been identified but are thought to be sesquiterpenes, which have been isolated from the related genus Lactarius and from Russula sardonia. Sesquiterpenoids that have been identified from R. emetica include the previously known compounds lactarorufin A, furandiol, methoxyfuranalcohol, and an unnamed compound unique to this species. The bitter taste does disappear on cooking and it is said to then be edible, though consumption is not recommended. The mushroom used to be widely eaten in eastern European countries and Russia after parboiling (which removes the toxins), and then salting or pickling. In some regions of Hungary and Slovakia, the cap cuticle is removed and used as a spice for goulash. Both the red squirrel (Sciurus vulgaris) and the American red squirrel (Tamiasciurus hudsonicus) are known to forage for, store and eat R. emetica. Other creatures that have been documented consuming the mushroom include the snail Mesodon thyroidus, several species of slugs (including Arion ater, A. subfuscus, A. intermedius, Limax maximus, L. cinereoniger, and Deroceras reticulatum), the fruit flies Drosophila falleni and D. quinaria, and the fungus gnat Allodia bipexa. Similar species Russula emetica is one of over 100 red-capped Russula species known worldwide. The related beechwood sickener (R. nobilis) is found under beech in Europe. Many, such as the bloody brittlegill (R. sanguinaria), are inedible; this species can be distinguished from R. emetica by the reddish flush in its stem. Among the edible lookalikes, there is R. padulosa, commonly found in Europe and North America. R. aurea has a yellow stem, gills and flesh under its red cap. The edible R. rugulosa—common in mixed woods in the eastern and northern United States—has a wrinkled and pimpled cap cuticle, cream spores, and mild taste. Another inedible species, R. fragilis, has notched gills, and its stem stains blue with naphthol. The uncommon European subspecies R. emetica longipes is distinguished by its longer stem and ochre gills. The paler European mushroom R. betularum, found in coniferous forests and moorland, is sometimes considered a subspecies of R. emetica. R. nana is restricted in distribution to arctic and subarctic