Fungi

Mushrooms and toadstools are the fruiting bodies of fungi. They are generally but not scientifically taken as the fungi that possess gills. Yet again the distinction between toadstools and mushrooms is not scientific but just popular perception, commonly taken as the edible types being mushrooms and non-edible toadstools, which if taken as an absolute can be a dangerous.

I am not an expert in this field, this coupled with the enormity of species in the UK of 10,000+ and the dangers involved in picking the wrong mushroom, have not attempted to identify all the shown species. However these are the species I have found and photographed in Cornwall.

Fungi are unusual organisms, they are neither plant or animal, and as such need to be classified in a kingdom of their own. The fungi we generally think of, are mushrooms and toadstools, but this is not the whole picture. Also included are the yeasts and moulds.

Physiology

Fungi are primarily water making up to over 90% of their composition. Mushrooms' and toadstools’ bodies can be divided into a stalk and a cap.

The stalk or stipe is cylindrical and is enlarged at its base. The cap crowns the stalk and if one looks on its underside there are gills or lamallae which radiate outwards from the centre.

The majority of the gills are connected to both the stipe and the rim of the cap. There are other gills that are only connected to the cap’s rim, these free gills ease the dispersal of spores from the gills. On many fungi, the stalk may have a ringed collar, an annulus.

Careful removal of a mushroom from the soil will produce root like structures on the enlarged end of the stalk. These filaments are hyphae. Hyphae are a part of a larger network the mycelium. The fine hyphae themselves eventually join together and form thicker strands rhizomorphs.

What we see on the surface i.e. the toadstool or mushroom is only the fruit body of the mycelium. Its function is only to disperse the spores. These spores are very small and difficult to see with the naked eye and appear as a very fine dust. The colour of the spores can be an important indicator in identifying species.

Toadstool Showing Gills and Hyphae

Feeding

Unlike green plants, fungi do not possess chlorophyll. This means that they do not produce their food from light via photosynthesis, instead they have to use other methods to feed such as the following.

Parasitic, feeding on other living plants. This is a one sided arrangement, the fungi only taking nourishment from the host and giving nothing in return. This can be such a degree that the host dies.

Have a beneficial arrangement with other plants such as trees. The fungi may take nourishment from their hosts but in return they provide water and minerals. This exchange is carried out at the hosts roots.

Grow directly in high organic mediums such as manure.

Grow on dead organic mediums such as leaf litter and rotting wood. Organic matter is digested by enzymes and chemicals produced by the mycelium. Fungi acquiring nourishment this way are known as saprophytes, from the terms sapos meaning dead and phyta plant.

Reproduction

The majority of fungi reproduce themselves via spores particularly mushrooms and toadstools. Spores themselves can be dispersed in different ways, mechanically fired by the fungus for example cup fungi, insects as is the case with stink horns, or just by wind. Wind dispersal can be great distances, the spores are hardy and light, which enable them to be carried up high into the atmosphere by air currents.

Fairy Rings

These are natural occurrences which have many supernatural stories tied to them, such as fairies dancing within the ring.

Fairy rings start when a spore finds a favourable location to grow. The first mushroom grows and from this the mycelium grows.

The mushroom dies away and over the year the mycelium grows out evenly in all directions, and in the next season on its edge, new mushrooms grow forming a ring. This process is repeated season after season, with the ring growing larger. Some rings continue to do this for centuries.

Within the ring there is a poor growing patch of grass. As the mycelium grows it exhausts most of the nutrients, plus it forms a thick mat underneath the soil restricting moisture. These conditions are not conducive to grass growth. Each year the mycelium expands, and the old section dies off allowing the grass to recover. So as the fairy ring expands so does the bare ring, this ring representing the current year's mycelium growth.

Mushrooms that commonly form fairy circles are the field mushroom and the fairy ring mushroom.

Useful Fungi

Man has taken a few fungi species and turned their cultivation into an industry. The two that spring to mind are yeast and the common mushroom.

Yeast has been used for many years to break down sugar into alcohol. This affect is not only to produce alcoholic drinks such as wine, but also in the making of bread. A by product of this process is that carbon dioxide is produced, this gas is what makes bread rise.

Mushrooms are now farmed commercially. By far the most cultivated is the common mushroom Agaricus bisporus. With the broadening of tastes, other edible species are readily available from supermarkets eg chanterelle and oyster mushroom.

Of all the fungi the most prized as a delicacy by gourmets is the truffle, this being particularly so in France. The truffle found in the UK is Tuber aestivum. This is a roughly rounded fungus with a blackish warty exterior. The interior is white when young but turns brownish as it ages. They grow underground to a depth of up to foot and so to find visually is impossible. Fortunately they have a strong odour, this is used to find them, traditionally using pigs but now, trained dogs.

Many fungi have been used in the past for medical purposes. Even modern man found a use, penicillin was once a valuable antibiotic.

Detrimental Fungus

Not all fungi are beneficial to man, a few are considerably detrimental. One of the most destructive elements to buildings is the dry rot fungus. This fungus will eat away wood including supporting structures. This it does incidously, usually the first indicator of damage is the emergence of its mushroom, by then the damage has been done. Dry rot will even penetrate brickwork. Once it has got a hold it is very difficult and expensive to eradicate.

In the garden, the honey fungus is extremely destructive to trees and shrubs. It parasitises plant roots, gradually sapping their strength and eventually killing them. This fungus is virtually impossible to eradicate once it has a hold, its spores persist in the soil for many years.

In the fifteenth century a small fungus ergot Claviceps purpurea indirectly caused death. In wet years this fungus was common on rye crops. The rye was made into bread. Some who ate the bread suffered strange effects on their personalities similar to that produced by LSD. Many of those affected were deemed to be involved in witchcraft and were burnt at the stake.

CAUTION

Many fungi are extremely poisonous. Some of these are hard to distinguish from non toxic species. Do not eat any that you have picked unless you are an expert. Additionally if collecting fungi, never mix edible and toxic ones in the same container.

When collecting fungi, if you are to pick poisoness species wear rubber gloves and wash hands as soon as possible.