Mycology

Discover More About Fungi

The attraction of fungi may in part be due to their mysterious nature, to that magic moment when a mushroom "mushrooms". In British grasslands and woodlands, especially in autumn, an immense range of fungi emerge from the soil, tree trunks, leaves, from all forms of rotting vegetation to release their spores and help ensure their continued existence. 

How Fungi Grow

Like streetlamps in a city, these mysteriously appearing fruitbodies are evidence of a further, unseen network. The actual fruiting bodies are only a reproductive stage of the organism, and a rather brief stage at that. The rest of the organism, in the form of cotton-like threads (hyphae), remains hidden beneath the ground. 

Hyphae (sing. - hypha) are the basic structural units of fungi, just as cells are in a plant. These microscopic tubes, en masse, are referred to as mycelium. They search out, utilise, distribute and recycle nutrients. Individual hyphae are too small to be seen with the naked eye but sometimes a number of hyphae will cluster together to form visible, cotton- wool-like mycelium or thick threads resembling bootlaces which are referred to as rhizomorphs. These can sometimes be seen under the loose bark of dead trees. 

It is complex aggregates of hyphae that form the varied fruitbodies we see appear. The mycelium may be perennial and may persist in the soil or substratum for many years, possibly centuries, and it can, over this time, spread for many miles. Mycelium plays an important part in the rotting down of fallen leaves, twigs and other organic debris and replacing nutrients in the ecosystem. Within their varied habitats fungi are usually the primary decomposer. 

A Separate Kingdom

Fungi are a separate kingdom on a par with plants and animals. They differ from plants in many ways, including a complete lack of chlorophyll, the green colouring matter that enables plants to obtain their nutrition through photosynthesis. Fungi, like animals, require the organic matter of other organisms for their nutrition. However, rather than using a stomach to accomplish digestion, fungi live in or on their own food supply and simply spread into new food as the local environment becomes nutrient depleted. 

About 80% of all plants grow in a mutual association with fungi, the fungus providing as much benefit for the plant as the plant does for the fungus. Many plants, from orchids to pine trees, will not grow without a fungal partner forming an intimate association of its mycelium with the roots of the plant. This is called a mycorrhizal association. 

Research at Kew

Many fungi have great potential as biological controls for insects, weeds, eel-worms, and plant pathogens and eventually may be used to reduce the use of toxic pesticides that cause environmental pollution. At Kew and elsewhere research is being done to utilise this potential. 

Fungi are remarkable organisms present in every type of habitat and ecosystem throughout the world. Estimates suggest that over 1.5 million species of fungi exist, but mycology (the study of fungi) is a relatively new science and less than 5% of these have yet been described. Vital work is being done by the Mycology Section at Kew to shed new light on these unknown species. There is no doubt that fungi are of immense ecological and scientific importance, yet there is still much to learn about them. 

Email mycology@kew.org