Amanita coacta (Amanitaceae, Agaricales) with a key to Amanita species occurring in Brazil

Amanita coacta was described from Amazonas State, Northern Brazil, in 1978 based on a single collection, and since then no more records have been reported. Sixteen collections of this species were made from Parque Estadual das Fontes do Ipiranga, Sao Paulo State, Southeast Brazil. These collections form a basis for a re-description including range variation of spore size and shape. An artificial dichotomous key to all Amanita species occurring in Brazil is also presented.