MYCOTAXON Volume 106, pp. 227–232 October–December 2008 Neotypification of Marasmius amazonicus J.J.S. Oliveira 1 , C. Puccinelli 2 , M. Capelari 2 & I.G. Baseia 1 1 jadson_oliver@yahoo.com.br — baseia@cb.ufrn.br Depto. Botânica, Ecologia e Zoologia Universidade Federal do Rio Grande do Norte Campus Universitário, CEP: 59072-970, Natal, RN, Brazil 2 puccinellic@yahoo.com.br — mcapelariibot@yahoo.com Instituto de Botânica, Seção de Micologia e Liquenologia Caixa Postal 4005, CEP: 01061-970, São Paulo, SP, Brazil Abstract — e holotype of Marasmius amazonicus was lost during the Second World War due to the destruction of the Berlin-Dahlem herbarium, and, given the nonexistence of isotypes, we propose a neotypification for the species. Key words — Marasmiaceae, diversity, neotropics, taxonomy Introduction e genus Marasmius was established by Fries’ Floram Scanicam, published in 1835–37, and currently contains around 2,000 widely distributed species. Marasmius amazonicus is one of the most beautiful members of the genus and belongs to series Leonini subsection Siccini section Sicci (Singer 1976). It was originally collected near Juruá Miry, Amazonas State, Brazil, by Ule in 1901 and sent to Germany, where Hennings (1904) described it as a new taxon, naming it aſter its native region. During the Second World War, the type specimen was lost aſter the destruction of the Berlin-Dahlem herbarium, where the original material was stored. Singer (1976) in his monograph of the tribe Marasmieae for Flora Neotropica gave a detailed description of the species aſter material collected in Bolivia, where he commented on the loss of the type, although without designing a neotype. is taxon was rediscovered in Atlantic Forest areas in Rio Grande do Norte State, more precisely in Parque Estadual Dunas de Natal (Dunes State Park of Natal), a conservation area noted for its rich species diversity and interesting discoveries (Baseia & Calonge 2005, Fazolino et al. 2008). erefore, the purpose of this paper is to establish a Brazilian neotype, providing a detailed description with comments and illustrations of the species.