| Division | # of species | Description |
| Oomycota | ~475 | "Water molds" and their terrestrial relatives. Unwalled flagellated spores and walled airborne spores. E.g., late blight of potatoes, downy mildew, saprolegnia (mold on living or dead insects, fish, frogs, etc. in water). |
| Zygomycota | ~600 | Sexual reproduction by zygospores; coenocytic hyphae; chitinous cell walls. E.g., Rhizopus (black bread mold), Entomophthora muscae (parasite on the housefly). |
| Ascomycota | ~30,000 | "Sac fungi". Sexual reproduction by ascospores formed in asci; some unicellular (yeasts); E.g., pink bread mold, bread and wine yeast, ergot disease of grasses, Aspergillus (a common mold on foods), Penicillium (used for production of penicillin and of Roquefort and Camembert cheeses). |
| Basidiomycota | ~25,000 | "Club fungi". Sexual reproduction by basidiospores borne by basidia. Septate hyphae. Mushrooms and toadstools, puffballs, bracket fungi, rusts, and smuts. |
| Deuteromycota | ~10,000 | "Fungi imperfecti", not known to reproduce sexually. E.g., ringworm, athlete's foot, spear rot of asparagus, root rot of wheat. |