Allopsalliota is a fungal genus in the family Agaricaceae. A monotypic genus, it consists of the single species Allopsalliota geesterani, found in the Netherlands. The specific epithet honors Dutch mycologist Rudolph Arnold Maas Geesteranus. Allopsalliota was circumscribed in 1998 to contain what was then known as Agaricus geesterani, a species first described in 1986 by Cornelis Bas and Paul Heinemann.
- "Agaricus geesterani Bas & Heinem. 1986". MycoBank. International Mycological Association. http://www.mycobank.org/MycoTaxo.aspx?Link=T&Rec=102999. Retrieved 2011-12-05.
- Nauta MM. (1998). "Allopsalliota, a new genus for Agaricus geesterani". Belgian Journal of Botany 131 (2): 181–90.
- Bas C, Heinemann P. (1986). "Agaricus geesterani spec. nov., a very remarkable agaric discovered in the Netherlands". Persoonia 13 (1): 113–21.