How the mushroom got its name

© Else C. Vellinga
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Original publication: Mycena News, April 2011

What do ‘spillcam’, ‘vuvuzela’ and ‘Connopus’ have in common?

All three words were used for the first time in 2010.

Now, we have a new genus name for Gymnopus acervatus but where do the other mushroom names we are using come from?

The white-dotted red-capped species with a white stalk which is enlarged at the base and has a white ring is a good one to look at in detail.

Amanita

Amanita “muscaria” © Michael Wood

The first person to call it Amanita muscaria was Lamarck, who included it in his 1783 catalogue of plants. He gave a lyrical description, with emphasis on the beauty of this mushroom, its wonderful scarlet cap, nicely covered with white plush dots. But he refers to older literature, in particular Linnaeus’ book Species Plantarum, published in 1753, where Linnaeus called the mushroom Agaricus muscarius. Linnaeus gave it only a one-sentence description, with references again to older books, where phrase names were used, like the mushroom with the red cap and the bulbous stalk—just the way we still describe this mushroom for friends and family. Linnaeus introduced the system of using two names to identify a species: one, a genus name (in this case Agaricus), the other a species name (muscarius). This system is still in use. However, Linnaeus and Lamarck used their genera, Agaricus and Amanita, in a much wider sense than we do now—both their genus names could be used for any gilled mushroom.

After these early writings the name remained in use for the next two hundred and fifty years and this is the name we still use for this species. It turns up in the 1821 book by Fries, Systema mycologicum, which is considered the real beginning of mycological systematics. An early record for California is provided by Murrill, an east-coast mycologist who visited the states of Washington, Oregon and California in the fall of 1911. Murrill wrote that he saw ‘Brilliant orange and red sporophores of this deadly species’ in the pine barrens of Newport, Oregon, and that fresh specimens were shown to him by Professor Setchell in Berkeley. Every guidebook has a picture of the fly agaric (its common name), and its bright red caps can be found all over the Northern Hemisphere, and even in the pine forests that have been planted on a huge scale in South America, Africa, New Zealand and Australia.

Linnaeus and Fries, both Swedish scientists, wrote their books in Latin. Lamarck on the other hand wrote his book in French. Linnaeus just gave a one sentence description, no picture, nothing, though, as an aside, he mentioned that the species ‘kills bugs and eradicates them promptly’. With Fries it is the same story, no picture, and a very brief account of this species. Lamarck is the exception with his vivid description in florid language. Nowadays, there is a set of rules for describing new species and genera, the International Code of Botanical Nomenclature, which applies to plants and to fungi. The rules keep changing and new versions are prepared by committees on the nomenclature of different organismal groups (there is a committee that looks carefully at the proposals concerning names of fungi) and then are voted on by the attendees at botanical congresses.

Some of these rules: All names for plants and fungi have to be unique; for instance: the name Melaleuca for a mushroom genus had to be changed, as there was already a tree genus called Melaleuca (widely planted in our area) and the mushroom genus is now called Melanoleuca. However, the names can be shared by animals and plants or fungi: European beachgrass and a sand wasp are both called Ammophila arenaria. Also within a genus, every species has to have a unique name, and in big genera such as Cortinarius and Russula this might ask for a creative and imaginative mind.

The name has to be published, on paper and distributed to libraries. This rule is at the moment under reconsideration, as many journals will soon be on-line only, without any paper copy. There are journals, such as Mycotaxon and the free journal North American Fungi, that still print some copies of the journal and send them to libraries, but will not send paper copies to subscribers.

The description of a new species still has to be in Latin. A diagnosis suffices, i.e. a short comparison with other species. This requirement is also constantly attacked, and the last 25 years have seen a stream of proposals to get rid of this requirement. The on-line translation services can translate from almost any language into another, but Latin—no, that is not in their repertoire. It is now almost as difficult for an English speaker as it is for a Chinese or Estonian person to write in Latin.

One collection, in a public herbarium, has to be designated as the type collection for the species. In this way the name is connected to a real specimen, which can be studied to resolve disputes. At first it seems common sense to have this in the code, but times are a-changing in this respect too. DNA sequencing has changed the way new taxa are discovered. DNA is not just in entire specimens— dried fruitbodies —but also in spores, hyphae, or material isolated from soil, wood or water, without any knowledge of what the organism looks like. Instead of material to keep in a herbarium, there is now just some DNA in a tube, somewhere. Recently, a hitherto completely unknown group of soil fungi was discovered, and given the provisional and prosaic name ‘Soil Clone Group I’. Shouldn’t it be possible to name such widespread organisms that are known from their DNA signatures? To give you an idea about the scale of this problem, in 2009 more than half the batches of ITS sequences deposited in Genbank came from environmental samples, without specimens. This number has steadily been increasing over the last ten years. New sequencing techniques will make this number grow ever more rapidly in the coming years.

And yet, in 2009 more new fungal species were described without DNA sequence data than with. In some cases it does indeed not seem to be necessary to have molecular data. When I described the local species Pseudobaeospora aphana, there were only DNA data available for one species in the genus, a species that is morphologically quite different. So, I decided that molecular data for the new species were not needed (but produced them later anyway). In a group of species with few morphological differences, where the variability within a species and between species still has to be determined, it helps enormously to have sequence data to sort things out.

Getting back to the example of the fly agaric with which we started: Collections of that species from Europe, Japan, Siberia, and throughout North America have been investigated and sequence data from several parts of their DNA have been compared. What we thought what was one species that could vary in colour from deep red, through pale orange, to yellow, turn out to be divided into several distinct groups: One group occurs throughout Europe and Asia and spreads into Alaska, while a second big group occurs in North America, with a subgroup in the Northeast. Besides these two big units, there are several smaller distinct groups, one in the southeast of the USA, and three on Santa Cruz island off Santa Barbara. The colour variations do not correlate with the DNA groups. At the moment, we are left without a species name for the widespread North American taxon—the name “Amanita amerimuscaria” is used informally, but it has not been published under the rules set out above. It looks like more work has to be done to establish the boundaries of this taxon and see whether those local variants and groups also have morphological characters so they can be more easily distinguished.

Fungal taxonomy remains a subjective business. Some French mycologists even say that a taxon is good enough to be a species when they can recognize it. Others say that a species has to differ in at least two morphological traits from its neighbours and others claim that a certain percentage of similarity in the ITS-region is all you need (the ITS is a specific part of the DNA that is widely used in fungal species recognition).

Yet, describing fungal diversity is more needed than ever. Though the exact number of undescribed species of gilled mushrooms is unknown, we do know that here in California many are still nameless, or only known under old and wrong names from elsewhere, such as Amanita muscaria. With easier rules, better infrastructure (including more data freely available on the web), and more people working in this field (this is wishful thinking on my part), it will happen!

One final remark, there is no rule in the code that says the person who describes a new species has to be a professional biologist. In Europe, most new species are described by people with other professions, from shop keepers to veterinarians. Yes, you can be involved too!