The Agaricomycetes are a class of fungi in the division Basidiomycota. In most cases, wood-decay fungi aren’t something terrible; they contribute to a healthy environment. Some fungi that belong to Agaricomycetes are entirely harmless, they can be edible or used as recreational drugs.
However, a lot of them are considered poisonous and dangerous such as Amanita phalloides, Lepiota josserandii, Galerina marginata, Inonotus rikii, etc. They are pathogenic fungi, mostly infecting trees, causing them to wilt and rot. When these fungi attack plants they are affecting their vigor and growth which can even lead to death.