Collins Mushroom Miscellany. Patrick Harding

the infamous red and white toadstool. As knowledge of fungi developed, the agarics were separated into a large number of different genera, each containing closely related species. Professional mycologists reserve the word mushroom for members of the genus Agaricus, which have free gills (not attached to the stem), a ring on the stem and dark-brown spores shed from pink gills. The genus includes cultivated mushroom (Agaricus bisporus), field mushroom (Agaricus campestris) and yellow-staining mushroom (Agaricus xanthodermus). Unfortunately, not all members of the genus are safe to eat; Agaricus xanthodermus is mildly poisonous. One result of this is the enigma of a poisonous ‘mushroom’, one reason why the recent list of recommended English names (see here) drops the mushroom name in favour of yellow stainer.

      If the terms mushroom and toadstool are confusingly interchangeable, the presumed etymology of the two words is equally complex. Several 19th century authors assumed that the word mushroom evolved from mussheron, which came from a French word, mouscheron. This was believed to be a derivation of mouche-eron, from an old French name for fly agaric (Amanita muscaria), which is most people’s idea of a toadstool rather than a mushroom. Other writers have attempted to make a link with the French word mousseron, still used in reference to certain edible fungi, and the word mousse, meaning moss; a habitat often frequented by edible fungi. Mousse also means foam or froth (hence the dessert of the same name) and this ties in with the early belief (recorded by Pliny) that fungi developed from a ‘kind of glutinous fome or froth’. Sponges were thought to originate in a similar way and this association may be at the root of the word ‘fungus’, coming from the Greek sphonggis, a sponge.

      Mushrooms were long believed to be formed from mud or the slime left by snails. This has raised the possibility that the term mushroom originated from the Greek word μυκηζ, giving us the Latin mucus, the likely origin of the term mycology, the scientific study of fungi. The word mycology was first used by the Reverend Berkeley in 1836, but it was some time before it replaced the earlier term fungology.

      In 1953 John Ramsbottom dared to argue that the derivation of the word toadstool was self-evident:

      A typical toadstool obviously might serve as a resting place for a sedentary bachtrian.

      His words were backed by a sequence of black and white photographs from The Times. These appeared to show a toad climbing on to a toadstool, although the images were later found to have been faked.

      While it is unlikely that the average toad spends much of its time sitting on a toadstool (but see here) there is a long history associating toads (and frogs) with fungi. The link is also found in names used throughout Europe and also in Africa, America and Japan. The earliest British reference is the word tadstole (1398), followed

      by toodys hatte in the 15th century. The link is also clear in the use of the old word paddock, meaning a frog or toad, in the term paddockstool. That it was toads rather than frogs that lent their name is probably due to the venomous nature of the former. Like fungi, frogs and toads were associated with mud and slime, but frogs lacked the venomous nature attributed to toads and many species of fungi.

      The most poisonous European fungi are found in the genus Amanita (see here). Here the fruitbody emerges through a sheet-like veil, the remains of which may be left as raised, wart-like spots on the surface of the cap. Some authors have argued that Amanita muscaria (fly agaric) is the archetypal toadstool. An earlier English name for it was wart caps; another possible link with the warty-backed toad. In 1953 a related species, Amanita citrina (false deathcap), was shown to contain bufotenine, a chemical first isolated from the toxic skin gland secretions of toads. Sadly for those seeking a common link behind the use of both toads and fly agarics for their hallucinogenic effects (see here), bufotenine does not occur in fly agaric. In addition, although bufotenine is structurally similar to psilocybin (see here), it is not the chemical responsible for the effects of toad’s skin gland secretions.

      Fungi are often associated with, or look like, animal dung. Tad was an old word for dung. Here is perhaps another derivation for tadstole or tad stool, with the word stool being used with reference to faeces rather than a seat. Some seek to explain a link with both the toad and dung theories via the French word for a toad, crapaud, but I consider that this falls between two stools! Finally, tode is a German word for death; throwing a different slant on the origin of the word toadstool. I prefer the association with toads, but the true origin of the word toadstool, as with that for mushroom, is lost in the mists of time.

The Fifth Kingdom

      Plants and Fungi under the Microscope (late 19th century)

      {SPL}

      The absence of eggs or seeds in the fungi resulted in a long-held belief that they arose by spontaneous generation. During the 17th century the respected naturalist Gaspard Bauchin considered fungi to be ‘nothing but the superfluous humidity of soil, trees, rotten wood and other decaying substances’. As late as 1804 it was argued that fungi resulted from shooting stars, even though 75 years earlier Micheli had shown that, under suitable conditions, fungal spores gave rise to the same kind of fungus from which they had originated.

      Carl Linnaeus summed up the method of separating the three kingdoms of nature when he wrote in 1751:

      LAPIDES crescunt. VEGETABILIA crescunt & vivunt. ANIMALIA crescunt, vivunt & sentiunt.

      This can be translated as ‘If a thing simply existed it was mineral. If it lived it was vegetable. If it also had senses then it was an animal’.

      Other schemes separated the vegetables (plants) from the animals on the basis of mobility, although this resulted in some scientists placing fungi and sponges in the same group; a problem alluded to by the great Victorian mycologists Cooke (see here) and Berkeley who began their book Fungi Their Nature, Influences and Uses (1875) with:

       The most casual observer of Nature recognizes in almost every instance that comes under his notice in every-day life, without the aid of logical definition, the broad distinctions between an animal, a plant, and a stone. To him the old definition that an animal is possessed of life and locomotion, a plant of life without locomotion, and a mineral deficient in both, seems to be sufficient, until some day he travels beyond the circuit of diurnal routine, and encounters a sponge …

      As long ago as 1784 a Frenchman by the name of Villemet had proposed that there should be three kingdoms: plant, animal and fungal, but for the following 200 years fungi were regarded by both the scientific community and the general public as occupying part of the plant kingdom. Professional mycologists worked within university botany departments or in the confines of botanical gardens such as at Kew.

      As a child in the 1950s I purchased The Observer’s Book of Common Fungi and was informed:

      Fungi belong to the vegetable kingdom but differ fundamentally from all other plants (except for a few degenerate forms) in that they possess no chlorophyll.

      In the 1960s radical new schemes for the classification of living organisms were proposed, but it was not until the 1980s that the concept of grouping living organisms into not two, but five kingdoms became widely accepted. Since then scientists have embraced the notion that fungi belong to the fifth kingdom, separate from animals, plants, Protozoa and Chromista (including bacteria). A quarter of a century on from this reclassification and the majority of the British public, along with sections of the media, have not yet caught up. As late as 2005 a ‘plant-tastic’ display at the Ashmolean Museum in Oxford depicted a collection of fly agaric