Collins Mushroom Miscellany. Patrick Harding
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Название: Collins Mushroom Miscellany
Автор: Patrick Harding
Издательство: HarperCollins
Жанр: Природа и животные
isbn: 9780007596683
isbn:
Most mycologists now recognise five main groups (phyla) within the fungal kingdom. These are Basidiomycota, Ascomycota, Glomeromycota, Zygomycota and Chytdridiomycota.
Members of the Basidiomycota produce sexual spores on the surface of special club-shaped cells known as basidia. The agarics, a historical term for mushrooms and toadstools with a mushroom-shaped fruitbody, belong in the Basidiomycota, in a class known as the basidiomycetes. Older schemes divided the agarics into some five orders, largely based on spore colour. Current thinking is to have just three orders: one order includes the boletes, such as the edible cep (Boletus edulis), with tubes in place of gills; a second embraces the crumblecaps (Russula spp.) and milkcaps (Lactarius spp.), typical of woodland habitats; and a third includes all other agarics.
The basidiomycetes also include puffballs and their relatives, bracket and crust-forming fungi, club and coral fungi, and most of the larger jelly fungi. Two other classes of Basidiomycota include the rusts, smuts and other plant parasites; in total, around 500 British species of microfungi which, unlike the basidiomycetes, do not produce large fruitbodies.
Candlesnuff fungus – Xylaria hypoxylon
{Stephen Dalton/NHPA}
Members of the Ascomycota, usually referred to as the ascomycetes, produce sexual spores inside elongated sac-shaped cells known as asci. This group includes morels and truffles which, along with some cup-fungi such as orange-peel fungus (Aleuria aurantia), have relatively large fruitbodies and are usually included in books about mushrooms. The ascomycetes also embrace thousands of species of cup fungi with miniature fruitbodies only a few millimetre across, most of which grow on rotting plant material. Those in a group known as the flask fungi also have tiny fruitbodies, but in a few species these are clumped together in a larger mass of black tissue; examples include King Alfred’s Candlesnuff fungus – cakes (Daldinia concentrica) and the aptly-named candlesnuff fungus (Xylaria hypoxylon). Xylaria hypoxylon Another very large group of ascomycete fungi have entered into symbiotic relationships with primitive algae or bacteria in organisms known as lichens.
Other ascomycotous microfungi include species that cause plant galls, such as witches’ broom on birch and leaf curl on peach. The group includes the commercially important singled-celled fungi known as yeasts. These frequent sugar-rich habitats such as ripe fruit and are essential aids for the making of leavened bread and alcohol. Powdery mildews on plants and a range of moulds are also included here. Many of these rarely, if ever, produce sexual spores, but spread by asexual means. Among the moulds, many of which contaminate foodstuffs including bread and jam, is one called Penicillium chrysogenum, the original species from which penicillin was isolated (see here). In Britain there are at least 5,500 named ascomycetes, including over 1,800 cup fungi and about the same number of lichenised species.
The other three phyla of the kingdom Fungi may be of little interest to the average mushroom hunter, but include some very important fungi. Although there are fewer than 20 named British species in the phylum Glomeromycota, they include those that are probably some of the most ubiquitous of all fungi, forming mycorrhizal (fungus root) relationships with a huge range of non-woody plants. Their significance is discussed on page 55. Included in the Zygomycota are common moulds such as species of Mucor and fungi that parasitise insects. One of these kills house flies and leaves the moribund insects stuck to window panes, each surrounded by a halo of spores. The final group, Chytridiomycota, has spores that are mobile in liquid. Not surprisingly, many are aquatic or live in damp soil.
Several other groups that were previously considered to be fungi have recently been placed in the kingdom Chromista, although their classification remains a contentious issue. Species in the kingdom Chromista are largely aquatic or require damp conditions. They include the diatoms and some species of seaweed. The most fungal-like organisms now placed with the Chromista include species of Pythium which cause ‘damping off among overcrowded seedlings. Species of Phytophthora, one of which causes potato blight, have been moved into the kingdom Chromista.
The slime moulds or Myxomycota have also been ejected from the fungal kingdom and now reside in the kingdom Protozoa. Although bearing fungal-like fruitbodies, these organisms are not composed of thread-like hyphae and include a mobile, amoeboid stage as part of their life cycle. In a number of common species this stage is readily visible as sick-like patches of white or yellow, on grass or rotting wood, usually after periods of heavy rainfall.
Devil’s fingers – Clathrus archeri, an Australian species now turning up in southern England
{Yves Lanceau/NHPA}
{Simon Booth/NHPA}
The mentality of the twitcher is not restricted to ornithologists. In 1979 the novelist John Fowles wrote of his experiences in France:
I came on my first Military Orchid, a species I had long wanted to encounter, but hitherto never seen outside a book. I fell on my knees before it in a way that all botanists will know. I identified, to be quite certain, with Professors Clapham, Tutin and Warburg in hand (the standard British Flora), I measured, I photographed, I worked out where I was on the map, for future reference. I was excited, very happy one always remembers one’s ‘firsts’ of the rarer species.
For mushroom hunters and even professional mycologists, life is not as simple as it is for botanists or ornithologists. First, there are far more species to contend with and many of these can only be identified accurately with the aid of a microscope. Secondly, there is no equivalent book to the British flora or handbook of British birds which describes all of the larger fungi that have been recorded from our islands.
For most amateur mycologists the thrill of a new discovery is restricted to identifying a mushroom that is new to the finder rather than new to Britain. Despite this, Carol Hobart, a dedicated amateur mycologist from my home city of Sheffield, has recently discovered two species that are new to Britain. Far from being insignificant little fungi they are both quite large agarics; one a relative of death cap in the genus Amanita, the other related to the field mushroom.
There are plenty of fungal species that have not previously been identified in Britain, or anywhere else for that matter; the problem is spotting that they are new and then getting the record verified. Even a record that is new to a region, even if not new to Britain, is important in helping to build a picture of the geographic distribution of the fungus, especially where the species is declining as a result of habitat loss, or spreading, possibly from a single, recent introduction. Just as blurred photographs of ‘a bird never seen before in Britain’ are unacceptable to the scientific community, the validation of a new fungal record requires back-up material as proof.
The accurate identification of a fungus can rarely be done in the field. At the very least СКАЧАТЬ