Aliquandostipitaceae, Jahnulales) Freshwater Hyphomycetes from the Brazilian Amazon

Nova Hedwigia, Vol. 111 (2020), Issue 1-2, 187–197 Article Published online July 2, 2020; published in print August 2020

Xylomyces (Aliquandostipitaceae, Jahnulales) freshwater hyphomycetes from the Brazilian Amazon

Letícia Martins Krause1, Patrícia Oliveira Fiuza2, Flavia Rodrigues Barbosa1* 1 Instituto de Ciências Naturais, Humanas e Sociais, Universidade Federal de Mato Grosso, Av. Alexandre Ferronato, 1200, 78557-267, Sinop, Brazil 2 Programa de Pós-graduação em Sistemática e Evolução, Universidade Federal do Rio Grande do Norte, Campus Universitário, Av. Senador Salgado Filho, 3000, Lagoa Nova, Natal-RN, 59078-970, Brazil * Corresponding author: [email protected]

With 12 figures and 1 table

Abstract: Xylomyces is characterized by the absence of conidiomata, conidiophores, conidioge- nous cells, and conidia. The genus only produces chains of large, dark, thick-walled, dry, multiseptate chlamydospores with or without constricted septa. During an investigation of aquatic hyphomycetes on submerged wood and leaf litter in a stream in the Brazilian Amazon, we found four of the accepted eight species of Xylomyces. Xylomyces acerosisporus, X. aquaticus, and X. foliicola are new records to the Brazilian Amazon, while X. giganteus is a new record for the southern Ama- zonian region. Xylomyces giganteus showed the highest relative frequency and occurrence and X. foliicola displayed an intermediate relative frequency and occurrence. Xylomyces acerosisporus and X. aquaticus showed the lowest relative frequency, while X. acerosisporus indicated the lowest relative occurrence. Descriptions, notes, geographic distributions, and illustrations are presented for all species of Xylomyces found in this study. We also provide a key and a table for all species. Key words: aquatic hyphomycetes; chlamydospores; taxonomy; tropical fungi

Introduction

The hyphomycetes represent the asexual phase of Ascomycota and Basidiomycota, form- ing an artificial group represented by microscopic species, which reproduce only by mi- tosis. Among them, Xylomyces Goos, R.D. Brooks & Lamore (Aliquandostipitaceae, Jah- nulales) is characterized by the absence of conidia and conidiophores and the presence of a multiseptate, brown, thick-walled single or catenate chlamydospores. In addition, the