Agaricus bisporus - the cultivated button mushroom
In short
White button, chestnut and portobello mushrooms are all Agaricus bisporus, harvested at different maturity.
What it is
Agaricus bisporus is the cultivated button mushroom. The white button, chestnut (cremini) and portobello sold in shops are all the same species, harvested at different stages of maturity and from different cultivated strains.
Where it grows
It is grown commercially on composted substrate rather than gathered, and is the most widely cultivated mushroom species in the world. Wild populations occur in grassland and disturbed ground across Europe and North America.
Why it matters commercially
Because it is cultivated rather than foraged, supply is predictable year-round - which is why it dominates retail volume even though many wild species are more prized in cooking.
Sources
- GBIF Backbone Taxonomy - Agaricus bisporus (J.E. Lange) Imbach
- FAO, production statistics for cultivated mushrooms
Never eat a wild mushroom based on a web page or an app. This profile describes a cultivated species; wild Agaricus look-alikes include species that cause serious illness.