Species of fungus
 ;templatestyles src="Template:Taxobox/core/styles.css" / ;
Agaricus californicus, commonly known as the mock meadow mushroom, or California agaricus, is a poisonous mushroom in the section "Xanthodermati" of the genus "Agaricus".
It is mildly poisonous, causing gastrointestinal upset in many individuals. The etiology of these symptoms is unclear and some individuals can eat it without experiencing symptoms, but since there is no way to tell who can eat the mushroom safely it is generally recommended against.
Description.
The caps are wide, white, sometimes with a grayish-tan center, dry, and either unchanged or yellowing slightly when bruised. The stalk is long and 1–2 wide, perhaps larger at the base. The spores are brown and smooth.
Differentiating "A. californicus".
"Agaricus californicus" is similar in general appearance to many other "Agaricus" species, especially to "A. arvensis", "A. bisporus", "A. campestris", "A. cupreobrunneus", and which are commonly collected for the table. Since "A. californicus" is toxic, differentiating it from other similar mushrooms is important.
"Agaricus californicus" – like many other "Agaricus" species of the section "Xanthodermati" – displays a yellowing reaction where its flesh has been damaged. Unlike "A. xanthodermus" (a close relative in the section "Xanthodermati"), "A. californicus"'s yellowing reaction is not always readily apparent and the annulus is smaller. Even in specimens where the reaction is not immediately apparent the addition of a basic solution such as NaOH or even Lysol will cause the reaction to become quite noticeable, making this a convenient way to distinguish between "A. californicus" and similar mushrooms.
References.
 ;templatestyles src="Reflist/styles.css" / ;
External links.
"Agaricus californicus" in "Index Fungorum" ;br ;
"Agaricus californicus" in MycoBank.