Ainsworth classification of Fungi - Flow chart with Example and Salient Features

Lets us begin with a definition of fungus.

Fungi are microscopic or macroscopic, eukaryotic, haploid, non-chlorophyllated, spore-bearing, filamentous, heterotrophic thallophytes which  reproduce asexually and sexually.

Geoffrey Clough Ainsworth (1905-1998)

He published this classification as a paper in a journal in 1966. Then modified and published in  "Ainsworth and Bisby's Dictionary of the Fungi" (1971) and "The Fungi. An Advanced Treatise" (1973)

Kingdom Mycota (Fungi) is divided into 2 Divisions

1. Myxomycota (Slime moulds)

• Slime moulds
• Characters of both animals and plants
• Not cellular, holocarpic diploid
• Amoeboid protoplasm without a cell wall
• Plasmodium: single, large multinucleate protoplast (coenocytic)
• Example: Physarum

2. Eumycota (True Fungus)

• True Fungus which is Cellular, filamentous, haploid, Unicellular or multicellular with Chitinous Cell wall
• Thallus made up of Hyphae and mycelium
• Example: Agaricus, Penicillium,

Myxomycota further divided into 4 classes

1.  Acrasiomycetes (Cellular slime molds)

Free-living assimilatory phase forming psuedoplasmodium 

Example: Dictyostelium

2. HydroMyxomycetes (Net slime molds): network like appearance   

Example: Labyrinthula

3. Myxomycetes (True slime molds): free-living saprobic plasmodium 

Example: Physarum

4. Plasmodiophoromycetes (endoparasitic slime molds) that lives inside a host 

Example: Plasmodiophora

This is a summarized video on Ainsworth classification of Fungi:

Eumycota is divided into 5 Subdivisions

1.Mastigomycotina

• Aseptate coenocytic, Asexual reproduction by zoospores (flagellated motile spores)
• Sexual reproduction: gametangial copulation
• Example: Albugo, Pythium, Saprolegnia

2. Zygomycotina

• Aseptate coenocytic, Asexual reproduction by non motile spores produced inside sporangium.
• Flagellated cells absent
• Sexual reproduction by gametangial fusion followed by resistant Zygospore formation
• Example: Rhizopus

3.Ascomycotina (Sac fungus)

• Called as Sac fungi as sexual ascospores are formed inside a sac-like structure called ascus.
• Septate, well developed mycelium
•  Asexual reproduction by nonmotile conidia, flagellated cells absent.
• Sexual reproduction by ascospores (often 8 in number)
• Ascocarp or fruiting body may be  apothecium (cup-shaped as in Peziza), Perithecium (flask-shaped as in Xylaria) or cleistothecium (closed as in Penicillium)
• Example: Saccharomyces, Penicillium, Peziza

4.Basidiomycotina (Club fungus)

• Most abundant and advanced group of fungus
• Called club fungi as basidiospores are formed on club shaped structure called a basidium
• Septate well-developed mycelium with dolipore septum; a a special type of septum.
•  Asexual reproduction by non-motile exogenously produced conidia.
• Sexual reproduction by basidiospores formed on basidia
• Example: Agaricus, Puccinia

5. Deuteromycotina

• Called Fungi imperfecti as sexual reproduction is absent
• Septate well-developed mycelium
• Asexual reproduction non-motile conidia sometimes organized to form sporodochia.
• Sexual reproduction absent 
• Example: Fusarium, Cercospora

Ainsworth’s paper: Ainsworth, G. C. (1966). A general-purpose classification of fungi. Bibl. Syst. Mycol, 1, 1-4.