Forest Pathology

Names of Fungi and Diseases

State University of New York, College of Environmental Science and Forestry

"You must follow the rules for naming fungi and diseases. We'll be watching!"

"Fungus" is singular; "fungi" is plural. Don't confuse them!

Names of fungi

Names of fungi, as with other organisms, consist of the genus followed by the species ("specific epithet"). The genus is capitalized, the specific epithet is not. Both should be underlined or italicized. Names of higher taxa (family, order, etc.) are always capitalized but never underlined or italicized. Here are some examples:

Nectria galligena is in the division Ascomycota.

Some fungi have common names, but not many. Common names may be capitalized or not, but they are never underlined or italicized. Examples:

The common name of Fomitopsis pinicola is "red-belt fungus" because it usually has a reddish margin.
Phaeolus schweinitzii has a velvety surface and looks like a brownish lump on the forest floor. It has common names like "velvet-top fungus" and "cowpie fungus."

Names of diseases

Diseases do not have formal latin names like organisms, but most do have common names. These names may be taken from the host, symptoms, pathogen, and/or the kind of disease. Sometimes, part of the latin name of the pathogen is included in the disease name. If so, it is never italicized, but if the genus is used, it is always capitalized. Disease names derived from country names are capitalized as usual in English. Examples:

The most serious disease of southern pines is fusiform rust.
The greatest tragedy in American forest history was the devastation caused by chestnut blight.
A major disease of conifers in the northern hemisphere is annosum root rot, caused by Heterobasidion annosum.
Disease names like Swiss needle cast and Dutch elm disease are not much appreciated by the Swiss and the Dutch!
Both conifers and hardwoods are often infected by Armillaria species, which cause Armillaria root rot. The same disease is often called shoestring root rot because the fungus produces black, root-like structures.

In addition to diseases, there are names for types of diseases that are similar. They differ in the particular host or pathogen and often in details of infection, etc., but follow a general pattern that can be used in thinking about the diseases as a group. Here are some examples:

Heart rots are often the most serious diseases in hardwood stands.
In western conifers generally, it is considered that mistletoes are the most serious diseases, but root and butt rots are probably a close second.

Pathogens are not diseases

Diseases and the pathogens that cause them are two completely separate entities. Always be careful to distinguish them. Being sloppy in language leads to sloppy thinking. Equating them leads you into the trap of focussing too much on the pathogen and ignoring the role of environment and host in development of disease.

Exceptions are rusts and powdery mildews, terms used for both the fungi and the diseases they cause. The following are examples of what NOT () to do:

A serious disease of Douglas-fir is Phellinus weirii.
Leptographium wageneri is a root disease spread by root to root contact.
Heart rots produce basidiospores in conks.

Arnold says you better follow these rules, or he'll be back!

Diseases and pathogens: general discussion
Introduction to fungi
Silvicultural Background
Forest Pathology home page
College of Environmental Science and Forestry home page