Genkalia aravindia sp. nov.: a new diatom (Bacillariophyta) associated with wet wall habitats from Eastern Himalayas and comments on the related genera

The genus Genkalia Kulikovskiy, Lange-Bertalot & Metzeltin is typically known from aquatic habitats; its occurrence in aerial habitats is unknown. The new species, Genkalia aravindia, was discovered in Sikkim, Eastern Himalayas, a biodiversity hotspot in India. It prefers aerophilic habitats and has a unique valve outline possessing a larger number of areolae than any other Genkalia species. The genus shows comparable features with the genera Adlafia Gerd Moser, Lange-Bertalot & Metzeltin and Boreozonacola Lange-Bertalot, M.S.Kulikovskiy & Witkowski in possessing uniseriate striae, round to oval-shaped areolae, and curved terminal raphe fissures. In India, there have been previous reports of Genkalia digitulus (Hustedt) Lange-Bertalot & Kulikovskiy (as Navicula digitulus Hustedt) from the Western Ghats and Gujarat region of India, but this is the first formal documentation of any species of Genkalia from India and the occurrence of this genus in the tropics.