Mushroom Classification

Basics of classification

Fungal classification is based on molecular phylogenetics (DNA analysis) and morphology (structure of fruiting bodies, spores, hyphae). Modern systematics differs significantly from traditional approaches — many species have been reclassified based on genetic data.

Taxonomic hierarchy

Kingdom → Division → Class → Order → Family → Genus → Species
Fungi   → -mycota  → -mycetes → -ales → -aceae → (Latin) → (Latin)

Example: Porcini

Kingdom:    Fungi
Division:   Basidiomycota
Class:      Agaricomycetes
Order:      Boletales
Family:     Boletaceae
Genus:      Boletus
Species:    Boletus edulis

Main divisions of the fungal kingdom

Basidiomycota (basidiomycetes)

The most important division for foragers. Includes the vast majority of cap mushrooms.

Key feature: spores form on specialised structures — basidia (typically 4 spores per basidium).

Main classes and orders:

Ascomycota (ascomycetes)

The second most important division. Spores form inside specialised structures — asci (sacs), typically 8 spores per ascus.

Examples in Portugal:

• Morels (Morchella) — prized edible fungi
• Truffles (Tuber) — underground fruiting bodies
• False morels (Gyromitra) — dangerous, contain gyromitrin
• Cup fungi (Peziza) — saucer-shaped fungi on soil

Other divisions

• Glomeromycota — arbuscular mycorrhizal fungi (do not produce visible fruiting bodies)
• Chytridiomycota — chytrids (aquatic fungi, parasites)
• Zygomycota (paraphyletic) — zygomycetes (moulds, insect parasites)

Key families for foragers

Amanitaceae (amanitas)

Key family features: volva at the stem base, ring on the stem, free gills.

Boletaceae (boletes)

Tube mushrooms — one of the “safest” groups for beginners. There are no deadly species among boletes (though some are bitter and inedible).

Cantharellaceae (chanterelles)

Cortinariaceae (webcaps)

• Deadly webcap (Cortinarius orellanus) — deadly, orellanine damages kidneys

Other important families

Nomenclature: how to read scientific names

Scientific names of fungi follow the International Code of Nomenclature for algae, fungi, and plants (ICN).

Binomial nomenclature

Each species has a two-part Latin name:

• Genus (capitalised, italicised): Boletus
• Species (lower case, italicised): edulis
• Full name: Boletus edulis Bull., 1782

The author of the description and year follow the name:

• Bull. — Jean-Baptiste Bulliard (described the species in 1782)
• Fr. — Elias Fries (Swedish mycologist, “father of mycology”)
• (Vaill. ex Fr.) Quel. — species first described by Vaillant, validated by Fries, reclassified by Quélet

Synonyms

Due to reclassification, many species have synonyms — old names. Check current classification at:

• MycoBank (www.mycobank.org) — official nomenclature database
• Index Fungorum (www.indexfungorum.org) — fungal name database
• Species Fungorum — taxonomic database

Spores and spore prints

A spore print is an essential diagnostic tool. The colour of the spore powder is one of the key features for determining genus and family.

How to make a spore print

1. Cut the cap from a mature (but not old) mushroom
2. Place the cap gills/tubes-down on white and black paper (half on each)
3. Cover with a glass or bowl
4. Leave for 4–12 hours
5. Carefully lift the cap and examine the print

Typical colours

Sources

1. Kirk P.M. et al. — Ainsworth & Bisby’s Dictionary of the Fungi (10th ed.)
2. Hibbett D.S. et al. — A higher-level phylogenetic classification of the Fungi // Mycological Research, 2007
3. MycoBank — www.mycobank.org
4. Index Fungorum — www.indexfungorum.org
5. Bon M. — The Mushrooms and Toadstools of Britain and North-western Europe