The fungi are the master recyclers, the giant saprophytes. They’re the black, dry, and white rots, the colourful fate of last week’s lasagna left in the fridge for too long, and the huge, grey walls of smelly mould that can ruin entire structures. They are also known as baker’s yeast and brewer’s yeast.

They’re what separates grape juice from Chateauneuf du Pape. Portobellos, morels, cloud ears, and truffles are among them. In fact, if it weren’t for the Fungi, the French would not be half as arrogant about their cuisine. They might also, but from the other side, be able to.

That puzzle will have to wait for another day. The first item of business should be to define the problem. What criteria do we use to categorise this group? We discovered no evidence that anyone is utilising a phylogenetic definition of the Fungi that is useful.

For those who have managed to avoid our prolonged, high-pitched screaming on the issue, a phylogenetic definition is one that is based on some explicit premise about a group’s relative location in phylospace.

For example, the last common ancestor of Triceratops and birds, as well as all descendants of that ancestor, is referred to as Dinosauria. “Triceratops + birds” may be a simple abbreviation for this.

A definition based on some arbitrary set of characteristics that approximate an implicit, unstated, and thus untestable notion of what a dinosaur “ought” to seem like is quite different from one supported some arbitrary set of characteristics that approximate an implicit, unstated, and thus untestable notion of what a dinosaur “ought” to look like.

An “apomorphy-based” definition is the name for the second sort of definition. It should be regarded with the same scorn as the use of maize starch to thicken a demi-glace, as M. Auguste Escoffier (at right) would. If we had to impose a phylogenetic definition on the fungi, the stem group “toadstools > toads” would be our first choice (all organisms more closely related to Basidiomycota than to Tetrapoda). That definition assumes that Metazoa and Fungi have a tight connection.

However, such a presumption should not stifle our progress. The Metazoa-Fungi link appears to be stable presently. This approach, on the other hand, would force us to include Microsporidia in the Fungi fraternity. Microsporidia may be classified as fungi by certain definitions, although they are more closely related to fungi than to toads. This definition would also put an end to pointless debates regarding whether Chytridiomycota should be classified as fungi.

To our shame, the above discussion may be beneficial for advanced students of the English conditional mode, but it ignores the facts of fungal phylogeny. The following instances demonstrate this truth. “Fungi have cell walls and generate spores,” consistent with Wikipedia.

Madigan and his associates (2003) Fungi, then, are ferns? Even thus far, the Tree of Life will not go. It just has a list of common names: “Mushrooms, rusts, smuts, puffballs, truffles, morels, moulds, and yeasts, as well as many less well-known species, belong to the fungal lineage.”

In other words, the fungus is described by listing a series of ambiguous, colloquial phrases, followed by a wholly arbitrary catch-all category. “What is fungi?” you might wonder. Fungi are a class of creatures and microbes that belong to their own kingdom, the fungal kingdom, because they are neither plants nor animals.

Fungi eat decaying organic debris, live plants, and even animals for food. They are unable to photosynthesize because they lack the green pigment chlorophyll, which is found in all green plants. Many are beneficial to the natural cycle as decomposers and return nutrients to the soil; nevertheless, they are not all harmful.”

What exactly is fungi? However, this definition may be applied to most microorganisms.

“These spore-derived nonmotile eukaryotes lack flagella and are nonmotile.” Dr. Fungus uses the words fungi, fungus, and fungal interchangeably. Take a look at the illustration. This drum could be beaten for a long period.

The issue is that, out of the hundreds of references and websites on the internet that profess to address fungi, none of the ones we looked at provided a reasonable definition. Some sites are quite helpful in listing various fungal features. However, the more characteristics mentioned, the fewer fungi they exclude (in any phylogenetic sense). The vast majority of sources just avoid the topic.

Finally, we are forced to concede that there is no universally accepted meaning for the term “fungus.” Fortunately, mycologists seem to be less bothered by this gap at the threshold of mycology than the fungi themselves. As a result, we will blatantly disregard the widening chasm at our feet, as is the universal practice of man and mushroom alike, and go on to other concerns.