russula

Any of a large group of fungi (see fungus), containing many species. They are medium-to-large mushrooms with flattened caps and many are brightly coloured. (Genus Russula.)

R. emetica is a common species found in damp places under conifer trees. Up to 9 cm/3.5 in across, the cap is scarlet, fading to cherry, and the gills are white. This mushroom tastes acrid and causes vomiting eaten raw, but some russulas are edible.