This is just a very brief look at the wonderful diversity and uses of fungi.
The fungi kingdom is the least understood of the kingdoms of Life on Earth. For centuries fungi were treated as the work of evil spirits, elves or witches; they were classed as mineral rather than animal or vegetable. Nowadays we know that fungi and neither animals nor vegetables, but they pre-date both in evolutionary terms
A fungus has no chlorophyll to convert the sun's energy into food; it relies on other plant and animal material, using enzymes to dissolve its food. In many ways, fungi are more closely related to animals than to plants.
Toadstools and mushrooms rot away after a few days, but they are just the fruiting bodies connected to long-lived underground fungal threads, called hyphae. The hyphae combine to form a mycelium, sometimes in the form of an expanding disc. Some types of mycelia can live for hundreds or even thousands of years.
A fairy ring consists of fungus fruiting bodies emerging around the edge of a mycelial disc that expands from its point of origin. The diameter of the fairy ring gives a rough guide to the age of the fungal organism.
At one time people referred to edible cap-and-stem fungi as mushrooms and all poisonous, inedible or doubtful ones as toadstools. The trouble was, fungi were distrusted by everyone, and very few of the edible and wholesome fungi were categorised as mushrooms, most fungi are neither good to eat nor are they poisonous: they are simply inedible. The rapid appearance of quite large fungus fruitbodies, which could emerge overnight following rain, makes it understandable in the past that fungi were treated with suspicion. The implication was that these toadstools had something to do with darkness and evil.
The biological kingdom of fungi is enormous, containing at least a million species and perhaps ten times that number. Fewer than 100,000 species (17,000 in Britain) have so far been described scientifically and given names.
As well as the familiar fungus, grassland and woodland mushrooms, toadstools, brackets etc, the fungal kingdom includes yeasts used in brewing and baking, moulds that grow on rotting fruit and vegetables, and rusts that infect not only greenhouse tomatoes but also all sorts of other plants in the natural environment.
Large fungi represent only a tiny part of the kingdom of fungi; most species either do not produce visible fruitbodies or produce fruitbodies that are so small that they are rarely seen except by fungal scientists under a microscope.Although they do not look at all like the mushrooms that most people are familiar with, it is tiny fungi that cause the human infections like ringworm and athlete's foot.
No one, not even experts, can identify all the fungi they find because a specimen can be non-typical or immature or so old that key identifying features are not visible.
Where there is water there are also fungi. Most fungi live on land, but a few live permanently in water. In grassland and woodland habitats fungi play key roles, without them most plants could not grow well, in fact orchid seeds can germinate only when infected by types of fungi. Not all fungus-plant interactions are mutually beneficial. Some fungi are parasites, feeding on, and in sometimes killing their hosts. Foresters fear infection of their plantations by certain virulently parasitic fungi, such as Honey Fungus.
We now know that over 95% of plants live in symbiosis with fungi, through what are called mycorrhizal interactions. The fungi link to the fine rootlets of trees, orchids and most other plants. The role of fungi as natural recyclers of dead plant and animal material is crucial to the survival of all other forms of life. Apart from a few bacteria, fungi are the only thing that consumes the tough material contained in dead wood.
We also get other benefits from fungi. Since the discovery of Penicillin, developed from a fungus discovered by the scientist Alexander Fleming in 1928, most other antibiotics have come from fungi. Now that bugs such as MRSA (methicillin resistant Staphylococcus aureus) are becoming immune to our current range of antibiotics new medicines are required