Short title: Amanita viscidolutea sp. nov. Amanita viscidolutea, a new species from Brazil with a key to Central and South American species of Amanita section Amanita Nelson Menolli Jr Marina Capelari 1 Instituto de Botânica, Caixa Postal 3005, 01061–970 São Paulo, SP, Brazil Iuri Goulart Baseia Universidade Federal do Rio Grande do Norte, CB, Departamento Botânica, Ecologia e Zoologia, 59072–970, Natal, RN, Brazil Abstract: We described and illustrated Amanita viscidolutea sp. nov. from specimens collected in the state of Rio Grande do Norte, northeastern Brazil. The main characteristics of the new species are its yellow pileus with white margin, the viscidity of the pileal surface, an exannulate stipe and inamyloid basidiospores. We also present an artificial dichotomous key to Central and South American species of Amanita (subgenus Amanita) section Amanita. Key words: Agaricales, Amanitaceae, Atlantic rainforest, taxonomy INTRODUCTION Amanita Pers. is a well known mushroom genus with global distribution. The genus is characterized by an usually mycorrhizal habit, hemiangiocarpic-schizohymenial development, lamellae usually white and free, white or pallid basidiospores, bilateral hymenophoral trama and longitudinally acrophysalidic stipe tissue (Bas 1969). Species of Amanita with basidiospores inamyloid, pileal margin radially sulcate- striate, lamellulae nearly always truncate, stipe development eccentric upward in the primordium (usually resulting in a bulbous base of the stipe in mature basidiomes) and a universal veil usually friable (occasionally limbate) were placed in subgen. Amanita sect. Amanita, according to the infrageneric classification of Corner and Bas (1962) and Bas In Press at Mycologia, published on March 19, 2009 as doi:10.3852/07-079 Copyright 2009 by The Mycological Society of America.