Collins Mushroom Miscellany. Patrick Harding

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СКАЧАТЬ bolete –Suillus grevillei

      {Laurie Campbell/NHPA}

      Fungi of grassland communities include field mushroom (Agaricus campestris) and species such as yellow fieldcap, previously known as egg-yolk fungus (Bolbitius titubans, was B. vitellinus), which feed on decayed grass leaves, dung and straw. Some 50 species of waxcap (Hygrocybe spp.) are largely restricted to old, unlimed, grazed pasture that has not had inorganic fertiliser added. This is a habitat whose area has declined by over 90% since 1930. Mown, unfertilised old lawns and even some cemeteries are also homes for waxcaps and other species that are unable to compete in grassland where lime and inorganic fertilisers have been applied.

      Other habitats that include fungi specific to them include coastal dune systems, where such rarities as the dune stinkhorn (Phallus hadriani) and dune mushroom (Agaricus devoniensis) are to be found. The fruitbodies of dune mushroom develop under the sand, only pushing through as the spores mature; possibly a strategy to cut down on water loss in what is a very dry environment.

      A strange group of fungi grows on burnt ground associated with bonfires, forest fires and the controlled or accidental burning of heather moorland. Such ‘phoenicoid’ fungi (as in phoenix-like, literally arising from the ashes) include the beautiful tiger’s eye or brown goblet (Coltricia perennis), a bracket fungus with a mushroom shape that is occasionally used in florists’ displays. Tiger’s eye also grows in other sites, especially on sandy, acidic soil. In contrast bonfire scalycap (Pholiota highlandensis), a brown toadstool, is restricted to fire sites in either woodland or heathland. Despite this limitation it is common and widespread, as are fire sites. It is often found with bonfire inkcap (Coprinus jonesii), which is only rarely found away from burnt ground. Several cup or disc-like ascomycete fungi inhabit fire sites, where the ground may be covered with their fruitbodies. One of these is the stalked bonfire cup (Geopixis carbonaria).

      Geopixis is occasionally found protruding from the mortar of garden walls or emerging from damp plaster inside houses. Both these sites are very alkaline (they have a high pH) because of their lime content. The fresh ash resulting from wood or heathland fires is also extremely alkaline, one reason why fresh ash should not be used as a garden mulch. Very few fungi or plants can thrive in such conditions, but it appears that many phoenicoid fungi are adapted to and even thrive in an environment that is toxic to other species.

      A relative of Geopixis is even more at home in our homes. Cellar cup (Peziza cerea) produces clumps of delicate, pale buff-coloured, cup-shaped fruitbodies up to 3–4cm across. It grows on damp mortar or earth in moist cellars and erupts from rotting sandbags (an increasingly common habitat in flood-prone areas). It is famous for its association with toilets, where the moist conditions of gentlemen’s urinals, or on a wall or carpet soaked by a leaking cistern may result in large numbers of the fruitbodies. Fortunately, cellar cup does little damage and may even be a useful indicator of the damp conditions on which it thrives. Such conditions may provide a foothold for a much more serious household fungus and one that is not found outside any artificial habitat in Britain; dry rot (Serpula lacrymans) (see here).

      Gardens, along with parks, playing fields and churchyards, provide important urban sites for mushrooms and toadstools. Mycorrhizal species (see here) that obtain their food from tree roots are common in gardens and parks, and even on pavements. Earthballs (Scleroderma spp.) frequently burst through tarmac or thrust up between paving stones. Toadstools that are mycorrhizal with garden trees include a range of boletes, especially red cracking bolete (Boletus chrysenteron) and species of milkcap (Lactarius) and brittlegill (Russula). Not all of these require mature trees; woolly milkcap (Lactarius torminosus) may form fairy rings around birch trees that are no more than 10 years old.

      Parasitic fungi species that parasitise and kill both trees and shrubs have more serious consequences for gardeners and park keepers. One such toadstool is honey fungus, which in older books went under the name Armillaria mellea and whose destructive nature is outlined in Chapter Twenty-two. Lawns are home to many species known as ‘little brown jobs’, of which brown mottlegill or hay cap (Panaeolina foenisecii) is the most common. This poisonous toadstool is not infrequently devoured by inquisitive young children and also by dogs, but the outcome is rarely serious, if worrying for parents and pet owners. I was pleased to find magic mushroom (Psilocybe semilanceata) growing on my own back lawn (see here), but lawn fanatics, along with bowling and golf green keepers are less enamoured of fairy ring fungus (Marasmius oreades), which often disfigures the turf on which it grows (see here).

      As the organic, recycling movement has spread so the garden compost heap has made a comeback. Microfungi and bacteria are responsible for the breakdown of organic waste, a process that may cause the compost to reach temperatures as high as 60°C. Such conditions are only tolerated by thermophilic (heat-loving) toadstools including some species of inkcap (Coprinus spp.). Older heaps are occasionally colonised by wood blewit (Lepista nuda), whose mauve-gilled fruitbodies are edible and excellent; a bonus for the organic gardener. The use of woodchip on paths and as a garden mulch has ‘mushroomed’ in the past 20 years, bringing with it a range of toadstools not previously encountered in gardens or anywhere else in Britain (see here). Equally, the growing of exotic plants in heated greenhouses and conservatories has resulted in increased sightings of tropical fungi in Britain. Among the most conspicuous of these is plantpot dapperling or yellow parasol (Leucocoprinus birnbaumii), a bell-shaped little toadstool recognised by its bright yellow, scurfy cap with a distinctly grooved margin. Its first European record, in the early part of the 19th century, was in Prague Botanic Garden.

      Another relatively new habitat has provided a novel home for a previously unusual British fungus. This is the very beautiful split-gill (Schizophyllum commune). Looking like a small furry bracket fungus from above, the underside reveals a fan-like, coralloid mass of branching gills. Most British records up until the middle of the 20th century came from south-eastern England, where it grows on fallen wood (especially beech) exposed to the sun. By the start of the 21st century I had begun to find it in the Peak District, possibly an example of a move northwards under the influence of climate change. As a thermophilic species it is more common in tropical regions, but it has now found a new home in Britain; plastic-wrapped bales of hay. The mycelium grows on the warm contents of the bags and its fruitbodies emerge through the plastic lining.

      Wood blewit– Lepista nuda

      {Laurie Campbell/NHPA}

      In 2002 the same fungus made headlines with its ability to grow in another warm place: the human body. ‘Fatal Fungus that Preys on Humans’ was the title for one newspaper story. The fungus mycelium has been found to cause mouth ulcers and toenail infections; hardly fatal, but the fungus can be much more of a problem for people suffering from a suppressed immune system, including those infected with HIV or anyone taking immunosuppressant drugs.

      Given that, unlike green plants, mushrooms and toadstools do not require light for the maintenance of their nutrition, it should come as no surprise that caves and old mines have been, and still are, used to grow edible mushrooms. In France the ordinary white mushrooms are still known as Paris mushrooms from the time when they were only cultivated in old mines beneath Paris. A number of fungi occur naturally in such habitats, including some microfungi that are not found anywhere else. Of the larger fungi growing in old mines, some species attack wooden pit props, such as the mine fungus (Antrodia vaillantii), a bracket fungus that also rots wooden СКАЧАТЬ