Newly recorded Monoraphidales (Bacillariophyta) species in Jiuzhaigou Valley, China

Based on a diatom diversity investigation in Jiuzhaigou Valley Natural Reserve,five species of Monoraphidales (Bacillariophyta) are reported as new records in China,namely Achnanthidium pfisteri Lange-Bertalot,Achnanthidium rosenstockii(Lange-Bertalot) Lange-Bertalot,Platessa ziegleri(Lange-Bertalot) Lange-Bertalot,Psammothidium lauenburgianum(Hustedt) Bukhtiyarova&Round,and Psammothidium scoticum Bukhtiyarova&Round.The microstructures of these five species were observed using LM and SEM,and their taxonomic characters and habitats were described here in detail.