Fungus covers a wide variety of plants from moulds and wet rot to mushrooms and toadstools. They grow in a wide range of environments, from fields to wood stumps, dung piles and leaf litter. Many varieties are edible, but equally a large number are poisonous if ingested. Some are deadly poisonous whilst similar species may be edible. Wild mushrooms can be interesting, but should not be picked unless you have someone with you who is very knowledgable about fungi.