These keys are, for the most part, specific to California. Links to other keys useful for the determination of California fungi can be found at Systematic Resources: Fungal Descriptions and Keys On-Line. Especially useful are the Pacific Northwest Key Council keys.
- Agaricaceae: Key to genera in the Agaricaceae in California (PDF) by Dr. Else Vellinga
- Agaricus: Trial Key to Common Agaricus Species of the Central California Coast (PDF) by Fred Stevens
- Arcangeliella: Key to the Genus Arcangeliella in California (PDF) by Herb Saylor
- Boletes: Field key to the Boletes of California (HTML) by Dr. Harry Thiers
- Boletes: Field key to the Boletes of California (PDF) by Dr. Harry Thiers
- Boletes: Technical Key to the Boletes of California (HTML) by Dr. Harry Thiers
- Clitocybe: Key to the Species of Clitocybe, Ampulloclitocybe, and Infundibulicybe in California (PDF) by Denise Gregory
- Cystolepiota: Key to the Cystolepiota species in western North America (PDF) by Dr. Else Vellinga
- Inocybe: Key to the Species of Inocybe in California (PDF) by Florence H. Nishida
- Inocybe: Artificial Key to Common and Noteworthy Species of Inocybe from the Pacific Northwest (PDF) by P. Brandon Matheny
- Puffballs: Key to Common California Puffballs (PDF) by Fred Stevens
- Salt Point: Common Mushrooms and Other Fungi of Salt Point, California by Dr. Mike Davis