There are more than 700 species of mushrooms, but only 200 of them are considered as edible, about twenty as poisonous and the remaining ones as innocuous. Mushrooms are vegetables reproducing by spores which are not-visible to human eye, nestled under the cap and capable of germinating into a mass of white branching threads called micelia. According to the species, mushrooms may have different shape and size. The majority of mushrooms consists of a body fruit and a cap; some exhibits a deep a spongy mass instead of a cap. They are usually classified in families, genres and species. The flavour of mushrooms depends on the type of wood on which they grow on and this explains their diversity according to their place of origin. In Mediterranean countries mushrooms grow up both in valleys and in mountains. The gathering season usually starts in April and lasts until November, when temperature gets more rigid. Nevertheless, the best gathering season is the rainy period at the end of summer when cool temperature helps the growth of the most precious varieties, such as porcini mushrooms.