Agaricus Linnaeus
Sp. pl.: 1171. 1753.

Agaricus is a genus of mostly medium to large gilled mushrooms. Well known members of the genus Agaricus are A. bisporus, the "button mushroom" common in supermarkets and A. campestris, the "meadow mushroom", a popular edible mushroom which is common in pastures and grasslands in many temperate areas of the world.

Principle characteristics of the genus Agaricus:

• Spore deposit chocolate-brown, purplish-brown, blackish-brown
• Lamellae free
• Stipe is clearly separable from pileus
• Annulus present
• Volva absent
• Spores smooth

Keys and descriptions of the genus Agaricus:

• Fred Stevens: Trial Key to Common Agaricus Species of the Central California Coast (60 KB PDF)
• Pacific Northwest Key Council (Margaret Dilly): Trial field key to the species of Agaricus in the Pacific Northwest
• Pacific Northwest Key Council (Laverne R. Chariton): Trial field key to the species of Agaricus in the Pacific Northwest
• MushroomExpert.com: The Genus Agaricus
• Illinois Mycological Association: Agaricus
• Kerrigan, R.W. (1986). The Agaricales (Gilled Fungi) of California. 6. Agaricaceae. Mad River Press: Eureka, CA.

Agaricus species known to occur in California:

1. Agaricus albolutescens
2. Agaricus altipes
3. Agaricus arorae
4. Agaricus arvensis
5. Agaricus augustus
6. Agaricus benesi
7. Agaricus bernardii
8. Agaricus bisporus
9. Agaricus bitorquis
10. Agaricus californicus
11. Agaricus campestris
12. Agaricus comptuloides
13. Agaricus comtulus
14. Agaricus crocodilinus
15. Agaricus cupreo-brunneus
16. Agaricus diminutivus
17. Agaricus fusco-fibrillosus
18. Agaricus fuscovelatus
19. Agaricus hondensis
20. Agaricus lilaceps
21. Agaricus micromegathus
22. Agaricus osecanus
23. Agaricus parkensis
24. Agaricus pattersonae
25. Agaricus perobscurus
26. Agaricus placomyces var. microsporus
27. Agaricus praeclaresquamosus
28. Agaricus rubronanus
29. Agaricus rutilescens
30. Agaricus semotus
31. Agaricus sequoiae
32. Agaricus silvicola
33. Agaricus smithii
34. Agaricus spissicaulis
35. Agaricus subfloccosus
36. Agaricus subrufescens
37. Agaricus subrutilescens
38. Agaricus summensis
39. Agaricus vinaceovirens
40. Agaricus xanthodermus