Naming fungi in Latin and figuring out what Latin names mean

In a scientific name the first word is always a singular noun in the nominative case. Conveniently, the ancient Romans have predetermined the gender and case. Unfortunately, sometimes the gender makes no sense in terms of actual gender, especially with inanimate objects.  In English these are always neuter (it), but in Latin they can be masculine feminine or neuter. 

The second word (the specific epithet) may either be

• an adjective to modify it (and thus matches it in gender, number, and case– but not necessarily declension)
• A noun that is unrelated in gender and case (rare)
• Or another noun in the genitive, indication possession or location, not necessarily matching anything about the first word

Let’s analyze some scientific names.

Agaricus bisporus   Check the ending of the genus first.   That’s what often determines the ending of the epithet.  Agaricus is a Latin word meaning “mushroom.”  Remember that the genus name is always nominative singular.  In this case it ends in –us, which makes it 2^nd declension, masculine.  The epithet bisporus means two-spored; thus it is an adjective modifying the genus name and must match the genus name in number, case, and gender.

Let’s compare this to Agaricus campestris, the meadow mushroom.  Agaricus is still a Latin word meaning “mushroom.”  However, you will notice that the campestris ending –is does not match.  “campester” in Latin means meadow and is a 3^rd declension noun. Thus this epithet has to be a noun.  Checking the tables above, you see that –is is a genitive ending for nouns in the 3^rd declension genitive.  Thus Agaricus campestris literally means “mushroom of the meadow.”

There are some common endings in the 3^rd declension that it will be helpful to know.

-loma means “fringe” and is always neuter 3^rd declension

Hypholoma (hyphal fringe)

Tricholoma (hair fringe)

Hebeloma (blunt or dull fringe)

-cybe means “head” and is always  feminine 3^rd declension

Hygrocbye (moist head)

Inocybe (fiber head)

Gastrocybe (stomach head)

Agrocybe (field head)

Conocybe (cone head)

Dermocybe (skin head)

Clitocybe (close head)

Psilocybe (naked head)

-ceps means “head” and is always  feminine 3^rd declension

Claviceps (club head)

Cordyceps (heart head)

-myces means “fungus” and is always masculine 3^rd declension

Hypomyces (below a fungus)

Tyromyces (cheese fungus)

Dacrymyces (teardrop fungus)

Zelleromyces (Zeller’s fungus)

-derma means skin and is always neuter 3^rd declension

Scleroderma (hard skin)

Hyphoderma (hyphal skin)

Cystoderma (bladder skin- referring to the shape of the cells in the cuticle)

Ganoderma (lustrous skin)

-opsis means “like” or “similar to” and is always feminine 3^rd declension

Hygrophoropsis (like Hygrophorus)

Phyllotopsis (like gills)

Tricholomopsis (like Tricholoma)

Coprinopsis (like Coprinus)

Clavulinopsis (like Clavulina)

Ramariopsis (like Ramaria)

Fomitopis (like Fomes)

-ellus (-ella, ellum), ulus (-ula,-ulum),  -ina, –idius are all diminutive—i.e. designating a smaller size

Lentinus, Lentinellus, Lentinula

Marsmiellus (small Marasmius)

Xeromphalina (small, dry Omphalina)

Coprinellus (little Coprinus)

Galerina (little Galera – now a defunct genus)

Gomphidius (little Gomphus)

Cantharellus (little drinking cup)

Cantharellula (little Cantharellus)

Hydnellum (little Hydnum)

Crucibulum (little crucible)

Scutellinia (little shield)

-phyllum means gills and is always 2^nd declension neuter

Schizophyllum (split gills)

Lyophyllum (loose gills)

Chlorophyllum (green gills)

Aphyllophorales (without bearing gills order)