Six new Frustulia species (Bacillariophyta) in Tierra del Fuego peatbogs, Patagonia, Argentina

During a survey of the freshwater aquatic diatom flora of two peat bog areas in Tierra del Fuego, southern Argentina, six taxa belonging to the genus Frustulia that could not be identified were observed. Comparison with the type material of Frustulia (Navicula) crassinervia separated the Tierra del Fuego populations showing some resemblance as a new species: F australocrassinervia sp. nov. The other five taxa are likewise described as new based on light and scanning electron microscopy observations and comparison with all known Frustulia species worldwide. Frustulia delicatula sp. nov., F. ellipticolanceolata sp. nov., F. fuegiana sp. nov., F. patagonica sp. nov. and F. yaganiana sp. nov. Comments are made on their taxonomic position and how they can be distinguished from other Frustulia species in this genus. Brief notes on the ecology and distribution of the seven taxa are added.