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 it will require the collection of specimens for further examination later or, if all else fails, to send to an expert. If possible, collect several specimens in all stages of development. Even if the mushroom subsequently turns out to be rare, there is no evidence that collecting fruitbodies will do any more damage than the picking of apples from a fruit tree. Collect the whole fruitbody; do not snap or cut off the stem base as this can result in diagnostic features being left behind. For species growing on wood, try to remove the fruitbody with some of the attached wood. A penknife is an essential part of the mushroom hunter’s kit.
Make a record of any features that may disappear in transit. These may include a distinctive smell, texture or colour change brought about by handling the fungus. Mushrooms need to be transported back to base in a manner that prevents them from drying out or being damaged, but never in a plastic bag where they will quickly disintegrate into a soggy mess. Kitchen foil, waxed paper or plastic tubs will protect the specimens. Before moving on, try to pinpoint the location of the find (GPS helps) and note the habitat, e.g. ‘among moss on a slope’ or ‘growing from a beech stump’. The identification of associated trees or other plants may require a leaf or bark sample.
The feature that is most useful for the identification of any fungus, and especially for mushrooms and toadstools, is the colour of its spore print. A spore print is obtained by placing the fruitbody, gill (or tube) face-down, on a piece of glass or white paper and leaving it for up to 12 hours. Cover the fruitbody to prevent it drying out and be aware that white spores may need to be searched for on white paper; however, coloured paper may distort the spore colour. The true colour is best observed from a thick deposit of the spores. Try to distinguish different shades; brown may not be enough. The difference between a rusty-brown or purple-brown spore print will help to narrow down the group to which the specimen belongs.
Good photographs (from above and below) of the fresh specimen can be useful, but a sketch using crayons or watercolour is often better. Remember to indicate the scale as size may be important. The colour of the spore print (if produced) should be included. At this point it should be possible to identify the specimen, at least to its genus, using one of several identification books aimed at the general public (see details on page 204). If this is not possible and an unusual find is suspected, a dried sample will be required to back up any photographs, drawings and notes. Unless it is very large (when the fruitbody will need to be sliced), dry the whole specimen above a radiator or another heat source.
The next course of action is to take the specimen to a member of a local fungus group (see here) or enquire whether any nearby museum has a fungus expert on the staff. If all else fails the dried specimen, along with the details outlined above, can be sent to The Mycology Section, Jodrell Laboratory, Royal Botanic