Disentangling the chaos of Fuscosporella reveals a new potential morphological adaptation to spore dispersal in aero-aquatic hyphomycetes

Abstract

Fuscosporella xingyiensis, collected from submerged wood in Malaysia and Taiwan, is described and illustrated with light and scanning electron micrographs. It is a dematiaceous hyphomycete producing ellipsoidal, muriform conidia with two lateral hyaline, sac-like appendages, one at each end of the conidium. This unique type of conidia for the first time is indicated to be formed by intercalary growth and differentiation and suggested as hitherto unknown further type of morphological adaptation to dispersal by water. In this paper, the genus Fuscosporella is also taxonomically revised. The taxonomic confusion originated from the confusion of two species in the original description of F. pyriformis, the type species of the genus. A new generic circumscription for Fuscosporella is provided, with correct illustration of F. pyriformis after careful examination of the protologue and holotype. The conidial dimensions of the five Fuscosporella species are compared and brief comments to each species are given according to the emended generic concepts. As evident from morphological and phylogenetic studies, there are currently four accepted species in Fuscosporella. Fuscosporella atrobrunnea is synonymized with F. xingyiensis, whereas Parafuscosporella lignicola is renamed as Vanakripa lignicola comb. nov.