Autumn is the best time to find mushrooms in the Maltese countryside. Humid soil and relatively warm weather induces several species to produce fruiting bodies – the part with which we are most familiar. But we should not make the mistake of thinking that these are the only type of fungi; many of them are so small that it needs a microscope to see them.

Little is known of the true biodiversity of fungi. It has been estimated that there are between one-and-a-half and five million species but only about five per cent of them have been formally classified.

Fungi belong to one of the six kingdoms that are presently recognised. At face value one would think of fungi as close to plants but at cellular level they are more similar to animals.

Fungi are important because they provide us with several drugs, such as penicillin, and food. Yeast which is used in leavening bread and to ferment sugars into alcohol is also a fungus.

Fungi are also very important for their role in decomposing dead organic matter. Some species are the cause of plant and animal diseases such as ringworm and athlete’s foot and rusts and leaf rot in plants.

Fungi feed by secreting enzymes on to dead or living organic matter. These enzymes break down the complex molecules into simpler ones which are then absorbed through hair-like structures known as mycorrhizae.

Fungi are normally sessile: they can spread into adjoining areas by growing into them or establish themselves by spore dispersal. Reproduction can be sexual or asexual.

The mushrooms we find in nature or sold for cooking are the fruiting bodies which exit from the substrate in which the fungus is growing, so that when it releases its spores these can be carried away by air currents. Large numbers of spores are produced and released by each mushroom to increase the chances that at least one lands on a suitable substrate.

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