Plant disease names vs plant pathogen names - they are two different things!

This is a pet peeve and perhaps belongs somewhere else, BUT you have a disease here, Beech bark canker, and a great photo of the pathogen, N. faginata. They are two different things. The latter causes the former.

If we have a great plant disease photo - can we name the disease?

If we have a great plant pathogen photo - can we name the pathogen?

Sometimes, when disease signs are obvious and host is known, we can name the disease and know what the pathogen is, but if you want to post a good pathogen image, can we get some macrophotography evidence?

In the above observation, I would prefer to see the pathogen name rather than the disease name because it is a good photo of the pathogen and not a good photo of the disease.

A disease is not an organism. The pathogen that causes the disease is the organism and thus can be placed within the iNat taxonomic framework.


There are some existing observation fields that could be used to note plant disease:✓&q=disease&commit=Search


The existing observation field “Disease Name” is appropriate in this case in my opinion.

I think the OP’s point is that iNat is giving the disease name as the common name of the pathogen, like Neonectria faginata (Beech Bark Canker).
That’s a little bit like putting Crocodylus niloticus (Bitten-Off Limbs) instead of Crocodylus niloticus (Nile Crocodile) so I see their point, although this is perhaps less the fault of iNat and more of the imprecision of daily language in which pathogens and their diseases are frequently used interchangeably (just look at how often Covid/Coronavirus are used both to refer to SARS-CoV-2 the virus and Covid-19 the disease).


You could call it Beech Bark Canker Fungus if that fixes the issue.


I think this is a general principle worth discussing here, but if there’s a detailed discussion for the specific taxon N. faginata, that should probably take place on a Taxon flag on iNat itself.

I understand the question a bit better given @DanielAustin 's comment and I think it suggests two questions:

  1. Is there a common name in usage for the pathogen that would be better to use than the disease name? If so it could be added to iNat and potentially made the default.

  2. Is the disease name the most common way that the pathogen is referred to outside iNat? If so, it may be best to use this name as the default on iNat because it is how most people know of the disease and would label their observations. Regardless, I don’t think that the disease should be removed from the common names list in most cases, since it probably will help some users. In the case of N. faginata, for instance, googling the species name seemed to lead to a fair number of Beech Bark Canker results so it seems to be in fairly wide use.


Seems this is a common issue with names for disease-causing organisms. For example, iNat uses White Nose Syndrome as the common name for the fungus Pseudogymnoascus destructans. But I don’t know a common name for that pathogen of North American bats unless you just tack on “fungus” after the disease name. Bat biologists just refer to the organism as Pd.

Added note: Pd has been shown to grow on substrates where bats are present or have been present, so it could be detected independent of the bats that it can infect. There’s no disease in these instances. So calling the fungus White Nose Syndrome is incorrect.


I just wanted to attract everyones attention that it is common in many languages to call the pathogen by the name of disease. Take, for example one of the largest plant pathogen databases EPPO, here is for Botrytis cinerea: or CABI:


I suppose that’s to be expected as the disease was often recognized and named before the pathogen was identified.

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How about “Beech Bark Canker [fungus]” to clarify it’s the organism not the disease. No invention of a common name needed.

There are some pathogens that have multiple hosts such as Gymnosporangium sabinae which is a heteroecious parasite and has Juniper as its primary host (winter) and Pear as its secondary host (summer). Commonly known as Pear Rust the pathogen expression in the two hosts outwardly appears different - observations to presence in Juniper and to presence in Pear
It would seem at least confusing to call this Pear Rust when seeing it in a Juniper yet that is how it is labelled.

I don’t see a problem, common name is just a common name, taxon is still in the system and you can easily see what group it is in.


Maybe not a problem but it is technically incorrect, and we strive for technically correct with a lot of things on iNat.

It is technically correct, there’re tons of organisms with common name of disease, when you name the latter you mean the first, this name should be in the list, otherwise it’s like saying casual users can’t id pathogens because they didn’t learn latin name of a fungi or bacteria that causes it.
And reread the initial post, does OP mean we can’t id disease as a pathogen?

Ask the OP.

I think you are correct in what the OP is stating. We use images of, audio clips of, feathers of, tracks of, scat of and etc. to indicate the presence of organisms in the form of actual presence, recent evidence of, or just evidence of. A disease is the manifestation of the presence of an organism at some point in time much like a city landscape is the manifestation of the presence of humans at some point in time.


In my experience, as a mycologist, plant pathologists use common names for organism and the associated symptoms interchangeably. Even if they use symptom-derived names they are usually implicitly referring to a specific causal organism (or group of related causal organisms). In that sense these are just different categories of common names. On iNat the scientific name for the causal organim can be associated with multiple common names for the symptoms so I don’t see the issue.

A bigger issue for me is that the majority of disease causing fungi cannot be reliably identified from the symptoms alone. Yes some can, but by no means all. There should be direct evidence, usually photos of the causal organism, and often microscopy to confirm the cause. If a common name leads people to think that diseases can be reliably named from symptoms alone, then we have a problem. I see lots of identifications made on the basis of symptoms that I would not accept.

I touched on this when somebody recently asked about insect versus fungal damage.


I agree. If people call the fungus by the disease name, then it’s not technically incorrect to have the common name of the fungus be the disease name. It’s just reflecting the reality of vernacular names commonly in usage. This page is an example of using the disease name and species name as synonyms. This may go against convention according to most people, but I wouldn’t say that makes it “technically” incorrect. Just unconventional.

The main use of common names in iNat is so that someone can type in a common name that they are familiar with and it will take them to the appropriate species taxon. If we remove disease names from the list of common names, then that functionality is removed.


That’s what I said.

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