ON MORPHOLOGY, TAXONOMY AND DISTRIBUTION OF THALASSIOSIRA BRAMAPUTRAE AND T. LACUCTRIS (BACILLARIOPHYTA) IN RUSSIA
Our analysis of published data and study of new materials on diatom previously attributed in the Russian literature to Thalassiosira bramaputrae (Ehrenberg) Hakansson et Locker have shown that it belongs to other Thalassiosira species, namely T. lacustris (Grunow) Hasle and has wider variability of main morphological features than was specified in its description. This has allowed the author to emend the diagnosis of T. lacustris and specify its distribution in Russia. The variety T. bramaputrae var. septentrionalis (Grunow) Makarova is considered here as T. hyperborea var. septentrionalis (Grunow) Hasle. The variety T. bramaputrae var. proximus (Makarova) Makarova is supposed to represent the largest cells of T. lacustris.