Part 66

4. Veil on the cap composed under the microscope of strings of sausage-shaped cells--group Lanatuli, e.g. C. cinereus, C. pseudoradiatus, C. radiatus (see p. 211)

Veil on the cap composed under the microscope of thick- or thin-walled, flexuous or straight, filamentous, hardly inflated cells--group Impexi, e.g. C. filamentifer Kühner, C. vermiculifer Dennis.

General notes on dung-loving fungi and their habitats

Dung fungi are highly satisfactory for demonstrating the diversity and morphology of a group of related organisms within a single ecological system, as representatives of most of the major groups of fungi usually grow on dung after a period of incubation. Dung will always produce characteristic fungi whatever time of year it is collected.

Dung is best incubated in a light place, for example on a window sill, in a warm room on layers of blotting paper or other absorbent material. For rabbit-pellets and samples of similar size petri-dishes are ideal, but for cow, horse and similar types of dung large covered dishes such as casseroles or sandwich containers are very good. Samples should not be kept in airtight containers for long periods of time as under such conditions animal life present rapidly breaks down the dung and induces anaerobic conditions. Instead larvae and earthworms should be excluded from the sample as they decompose the dung and inhibit fungal growth but their activity can be reduced, if causing a problem, by spraying the sample lightly with a proprietary fly-kill aerosol.

By keeping the dung under constant observation during incubation a whole succession of fungi can be seen. Thus the first fungi to appear are the moulds which although numerous need a microscope for their identification. The moulds are followed by a series of Ascomycetes (Sporormia & Sordaria with flask-shaped fruit-bodies and Iodophanus, Coprobia and Cheilymenia with disc-shaped fruit-bodies), which are best sought with the use of a powerful hand-lens or a stereoscopic binocular microscope when their full beauty will be revealed. However, because they need the aid of instruments even to see them they cannot be considered larger fungi. The fruit-bodies of the Basidiomycetes are readily seen with the naked eye, but a hand-lens is still very useful for observing features of the cap and stem, particularly the veil characters. The Basidiomycetes usually conclude the succession of fungi found on dung and soon after this state the dung is colonised by mosses and higher plants and later it is fully incorporated into the soil.

Dung is a very useful substrate for studying succession. However, equally interesting results can be obtained from observing the fungi which appear on a stump, colonise a newly laid lawn, or indeed those growing on refuse such as a cast-out rug; microscopic and larger fungi are all to be found.

If the dung cannot be incubated immediately it should be dried quickly, for most dung-fungi will survive such treatment and grow when the sample is remoistened. The blotting-paper on which the dung is placed should be kept moist throughout the incubation period.

One large discomycete (up to 80 mm across) occurring on manure-heaps must, however, be mentioned, this is Peziza vesiculosa St Amans (see p. 200); the inner surface of this cup-fungus becomes detached from the flesh at maturity and forms blisters.

(ii) Fungi of bonfire-sites

~Pholiota highlandensis~ (Peck) A. H. Smith

Charcoal pholiota

Cap: width 20-50 mm. Stem: width 4-8 mm; length 25-60 mm.

Description: Plate 73.

Cap: convex then flattened and slightly umbonate, smooth, very sticky at first, but becoming shiny when dry, orange-yellow to sand-colour; the margin is first incurved and ornamented with filaments from the veil, but these are soon lost.

Stem: dirty yellow, darker towards the base, cylindric or narrowed downwards and covered in small fibrillose scales.

Gills: clay-coloured then dull brown, adnate and crowded.

Flesh: yellowish.

Spore-print: dull rust-brown.

Spores: medium-sized, ellipsoid, smooth, dull brown under the microscope and 7-8 × 3-4 µm in size.

Facial cystidia: spindle-shaped with obtuse apex.

Marginal cystidia: similar to facial cystidia but usually smaller.

General Information: This fungus which occurs from spring to autumn is recognised by the habitat, colour of the fruit-body and the spore-size. It is known in many books as Flammula carbonaria (Fries) Kummer, but the genus Flammula is no longer used for it refers to a flowering plant in the buttercup family.

P. highlandensis is the same fungus as that referred to as Pholiota carbonaria by European Mycologists, but this name cannot be used for it refers to an entirely different N. American species. ‘Highlandensis’, in fact, refers to the locality where the present fungus was first found in the United States of America. The true P. carbonaria A. H. Smith has only been found once in Europe and this only recently in the south of England. It differs in the reddish orange scales on the stem; indeed it is a much brighter fungus than the common charcoal Pholiota.

~Tephrocybe anthracophila~ (Lasch) P. D. Orton

Cap: width 1-4 mm. Stem: width 1 mm; length 2-5 mm.

Description: Plate 73.

Cap: blackish when wet, drying sooty brown, slightly depressed in the centre, smooth, and viscid.