A brief introduction to the classification of fungi

There are thought to be an enormous number of species of fungi. In Britain over 15,000 species have been identified. This is about 6 times the number of species flowering plants. About 3000 of these are species of larger fungi i.e. those with fruit bodies easily visible to the naked eye, and the majority of these belong the sub-division Basidiomycota. A problem for every beginner is that there are common names for only a very few of these species and use of the correct scientific name is almost always necessary. Scientific names have two parts: the first indicates the genus and the second is the species epithet. To use a familiar example, everyone uses the term Clematis for the garden climber and this is in fact the genus name. The full name of the wild clematis is Clematis vitalba and this name is unique. After a while these genus names become very familiar so that you do not need to think before using them. The trick is to get to know the genera first and then there is only the specific part of the names to remember.

The other sub-division of fungi that forms large fruiting bodies is the Ascomycota. (Note that in many texts you will find these groups called Basidiomycetes and Ascomycetes which are the equivalent Class terms). There are several other sub-divisions of the fungi and some information about each is provided in the table below. The main feature used in designating all these different groups is the structure of the spore producing organs. In this respect, fungal taxonomy is akin to botany. It is not surprising that with so many different forms and groups the language used to describe the fungi is utterly confusing! I can only suggest you take things slowly and don't try to remember too much too quickly. The various other pages in this site illustrate many of the differences and will (hopefully) help you find your way. 

 

Sub-division

Characteristics and remarks

Basidiomycota

Contains the familiar mushrooms and toadstools. Divided into a number of classes including the Gasteromycetes (includes the puffballs and stinkhorns) and the Teliomycetes (includes rusts and smuts). The familiar gilled and pored fungi belong to the Hymenomycetes. All members of the Basidiomycota produce their spores on a characteristic cell called a basidium (plural basidia)

Ascomycota

The largest number of species occur in this section. Includes the class Discomycetes (the cup fungi) and the Pyrenomycetes (flask fungi). Members of the Ascomycota produce spores in a sack like structure called an ascus (plural asci).

Zygomycota

Mostly microscopic species includes the pin moulds that attack fruit in your refrigerator.

Oomycota

Not now considered to be related to the above three sub-divisions. The Oomycota includes the water moulds and some important pathogens such as potato blight. Many have produce motile spores during their life cycle which can swim.

Deuteromycota

An artificial sub-division containing those species for which no sexual state has been identified and therefore cannot be placed in any of the above sub-divisions. Most are thought to be derived from the Ascomycota. Includes many so called moulds such as Penicillium

Myxomycota

The slime moulds. Very different from any of the above although spores are produced which look like the spores of the higher fungi. Many species  include an amoeba-like stage in their life cycle.

 

 

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