Classification of Fungi

The complex of environmental conditions that determines the way of life, range of distribution and population abundance of a given fungal species is called the species' biotope. The biotopes of individual species differ in size. The smaller the biotope, the smaller the species' chance of spreading, and this determines the survival of that species or even of an individual of it. For this reason every species, as if taught by nature, strives by every means available to it to preserve its innate properties, to improve them, seeking somehow to widen the boundaries of its biotope, but never to narrow them.

The spread of fungi and their adaptation to a given biotope are determined by the following rather important factors: the hyphal structure of the fungal thallus, its growth form, the contact of the thallus with the substrate, the active metabolism of its cells, rapid conquest of the substrate, great adaptive capacity and the ability to produce toxic substances in order to preserve or extend its habitat.

To better understand the relationships between individual fungal species, the fungi themselves, their way of life, their impact on the environment and the possibilities for their use, one must first study fungal species, determine how many there are, and only then classify them, i.e. build a system of the fungal kingdom.

To designate the names of fungi, as with plants, animals and other living organisms, scientific as well as popular literature uses the binary (double) nomenclature introduced by C. Linnaeus in 1733. Every fungus (plant and animal) is named in Latin with two words. For example, in Boletus aereus – the bronze bolete – the first word is the name of the genus, always written with a capital letter, and the second is the species name, written with a lowercase letter.

The natural system of fungi (as of the entire living world) exists only in nature, while scientists, on the basis of the available data and well-founded knowledge, merely try to create as perfect and convincing an artificial classification as possible. At present more than one system of fungal classification has been published; mycologists understand them differently and interpret them in different ways. There is as yet no single system of fungi acceptable to all mycologists.

According to the latest classification, published in 1995, the world of fungi was divided into 11 divisions. However, barely five years later, as new scientific facts accumulated, this system of fungi was refined and corrected. The classification of fungi given by Moreau, 1978 remains popular in the mycological literature even today. Mitosporic fungi lack a sexual stage or have lost it (mostly ascomycetes or some basidiomycetes), and therefore do not form a separate division. In older literature they were placed in a separate division (Deuteromycota). Recently the slime moulds (Myxomycota) have been transferred to the kingdom Protista, and the oomycetes (Oomycota) to the kingdom Stramenopila.

The founder of the systematics of the fungal kingdom is considered to be the Swedish botanist Elias Fries (E. Fries, 1794–1878). In 1821–1822, in his work "Systema mycologicum", he presented a system of fungi whose foundations have not become outdated even now.