Russula xerampelina

Russula xerampelina was originally described in 1770 as Agaricus xerampelina from a collection in Bavaria by the German mycologist Jacob Christian Schaeffer, who noted the colour as fusco-purpureus or "purple-brown". It was later given its present binomial name by Swedish mycologist Elias Magnus Fries. Its specific epithet is taken from the Ancient Greek meaning "colour of dried vine leaves", xeros meaning "dry", and ampělinos or "of the vine". Two subspecies have been recognised, var. xerampelina and var. tenuicarnosa, with thinner flesh in the cap and the stipe. The name R. erythropoda is now considered a synonym, and former subspecies R. (xerampelina subsp.) amoenipes (originally named by Henri Romagnesi) now a separate species. A former variety with a greenish cap, R. xerampelina var. elaeodes, is now classified as R. clavipes. Recent studies show that Russula xerampelina is actually a species complex, with at least three species: R. xerampelina, R. clavipes, and R. graviolens. Sometimes, more than three are recognized, including R. olympiana. As the first defined species, it gives its name to the section Xerampelinae, a group of related species within the genus Russula, occasionally all termed R. xerampelina in the past. Common names include shrimp mushroom, shrimp Russula, crab brittlegill, and shellfish-scented Russula. == Description ==

Russula xerampelina has a characteristic odour of boiled crab or shrimp. Trimethylamine and its precursor, trimethylamine , are the source of this mushroom’s distinct odour. The cap is wide, domed, flat, or with a slightly depressed centre, and sticky. The colour is variable, most commonly purple to wine-red, or greenish, and darker towards the centre of the cap. There are fine grooves up to 1 cm long running perpendicular to the margin. The stipe is long, wide, cylindrical, white or sometimes with a reddish blush, bruising brown. Similar species More reddish-capped forms could be confused with the sickener (R. emetica), although the latter always has a white stipe and gills; greener-capped species may resemble R. aeruginea. Many other species in the genus are similar, e.g. R. graveolens, but most lack the seafood smell. Russula olivacea has a more velvety cap. == Distribution and habitat ==

Russula xerampelina is widely distributed; quite common in northern temperate zones, and often ranging into the Arctic Circle, it also ranges south to Costa Rica. In North America, it appears from July to October to the east and October to January in the west. and seems to have a preference for Douglas fir, or more rarely pine trees or larch. It is sometimes found in deciduous woods, such as beech and oak. Variety tenuicarnosa has been found on sandy soils under pine in Slovakia and northern Italy in Trentino. == Uses ==

The flavor is mild. This russula is considered one of the best edible species of its genus, although the shellfish smell will persist even when cooking. This is less pleasant in older specimens. The young caps are said to be superb stuffed with any suitable ingredients, and are rarely maggoty. == See also ==