The Shaggy parasol is the common name for two closely related species of mushrooms, Chlorophyllum rhacodes and C. brunneum, found in North America and Europe (the latter species is also found in Australia).
The shaggy parasol is a large and conspicuous agaric, with thick brown scales and protuberances on its fleshy white cap. The gills and spore print are both white in colour. Its stipe is slender, but bulbous at the base, is coloured uniformly and bears no patterns. It is fleshy, and a reddish, or maroon discoloration occurs and a pungent odour is evolved when it is cut. The egg-shaped caps become wider and flatter as they mature. The stem of C. rhacodes grows to 10 to 20 cm (4 to 8 in) tall. The cap grows to 7.5 to 20 cm (3 to 8 in) across, while the stipe has a diameter of 1 to 2 centimetres.
Source: en.wikipedia.org/wiki/Shaggy_parasol - 17.01.2011
The Shaggy Parasol contributes its part within the organism alliance by the decomposition of the surrounding organic material, which is responsible for the development of mould.