Fungi of Thames Ditton and Weston Green
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| Aseroe rubra (starfish fungus) discovered at Oxshott in 1993. The only known locality in the northern hemisphere. (copyright Sandra Rickwood) |
The approach of autumn signals the start of the main season for larger fungi. Fruitbodies of many forms and colours appear in local woods and fields, heralding an exciting few weeks for the growing number of fungus hunters. Larger fungi include the familiar mushrooms and toadstools and their many relatives, brackets, fairy clubs, jelly fungi, puffballs, stinkhorns and others. More than 3000 such species occur in Britain, and several hundred of them can be found in this area. But larger fungi, with fruitbodies large enough to handle, represent only a fraction of the true number which occur. Fungi are immensely diverse, with an estimated 1.5 million species worldwide, most of them yet undescribed. In Britain at least another 9000 species occur, microfungi with tiny fruitbodies found on rotting leaves and stems, or sometimes as parasites on plants and even animals. Many of them, especially the rust fungi and powdery mildews, so damaging at times to ornamentals and crop plants, will be familiar to gardeners. Autumn is also a good season for them, though fungi of some sort can be found throughout the year.
Although long treated as plants, fungi belong in fact in their own Kingdom, radically different and much more diverse than the plants. They occur everywhere, in all habitats from the poles to the deep sea, and are amongst the most diverse and numerous of all organisms. What are all these fungi doing and what do we know about them? Increasingly, the immense importance of fungi is being realised and they should be seen as essential to every aspect of our lives. Without fungi other life could not exist. The most fundamental process of all, the decay of organic matter and recycling of nutrients, is almost entirely handled by fungi. Mycorrhizas, intimate associations between plant roots and fungal hyphae, essential to the healthy development of both partners through exchange of water and nutrients, are now known to occur in virtually all plants. It is a partnership which developed half a billion years ago, so important that without it plants may never have colonised the land. Fungi provide food for many animals, including mammals and invertebrates, either directly or by the fermentation activities needed for bread, alcohol and many other products worldwide. Their role in medicine also cannot be overstated; antibiotics, for example, are all produced by fungi. Although many fungi are parasites, in natural environments these play essential roles in regulating plant and animal populations and only in the artificial conditions of horticulture and agriculture can they become a problem. However, many fungi are now threatened and of increasing conservation concern due to loss of habitats and pollution. Ancient woodland and old, unimproved meadows, home to many now rare fungi, have almost disappeared in many areas. Such grasslands support the colourful waxcaps, Hygrocybe species, as well as many other fungi sensitive to nitrate fertilisers. Many of them are now rare. There are few such grasslands left around Thames Ditton, but local churchyards, long managed without fertilisers, can be productive.
Almost any of the grassy and wooded areas around Thames Ditton, as well as private gardens, can prove rich in fungi. Ditton Common has interesting records of the huge bracket fungus Rigidoporus ulmarius on old elms stumps, a good substrate but regrettably now mostly lost in the wake of dutch elm disease (also caused by a fungus, but an introduced one which proved new to science). Woodchip mulch, increasingly used locally, has become, curiously, one of our richest habitats for fungi including rare species and many which have proved new to Britain or even to science. Look there for the distinctive Agrocybe rivulosa, an unknown species just 5 years ago, described from the Netherlands in 2003, discovered in Britain in 2004 and now widespread and common! It has large brownish fruitbodies with conspicuous ring on the stem and grows usually in large clusters. Areas around the Dittons are also worth noting for their fungi. Barely a stone's throw away the extensive woods and heaths of the Esher/Oxshott Commons, a Site of Special Scientific Interest, is the most extensively recorded area of its size in the world. Over 3300 species have been recorded there, including new species and new British records, and many more await discovery. One of the most interesting is the unmistakable starfish fungus, Aseroe rubra, a southern hemisphere species related to our common stinkhorn (Phallus impudicus), first found at Oxshott 15 years ago. Oxshott is still the only known site for this species in the entire northern hemisphere!
Fungus hunting has become popular in recent years, particularly for culinary purposes. Many good edible species can be found locally, but collect with care as toxic species also occur. Death cap (Amanita phalloides), for example, one of the most poisonous of all toadstools, grows locally under oak and is quite common in some years. And don't over collect - fungi are essential to many creatures and are a valuable part of our local environment.Brian Spooner
Brian Spooner
Head of Mycology at Kew Gardens