New records of species of Achnanthidiaceae (Bacillariophyta) in Ganzi, Sichuan, China

During an investigation of diatom diversity in the Ganzi Tibetan Autonomous Prefecture, Sichuan Province, China, eight species and one variety of Achnanthidiaceae were identified as new records in China. They included: Achnanthidium atomus Monnier, Lange-Bertalot & Ector, A. straubianum(Lange-Bertalot) Lange-Bertalot, A. pseudoconspicuum(Foged) Jüttner & Cox, Eucocconeis aretassi(Manguin) Lange-Bertalot, Planothidium lanceolatum var. minor Cleve, P. oestrupii(Cleve-Euler) Edlund, Psammothidium sacculus(Carter) Bukhtiyarova and P. didymum(Hustedt) Bukhtiyarova & Round. The species were observed using light microscopy (LM) and scanning electron microscopy (SEM), with morphological characters and habitats described in detail.