Abstract
The most important item is accurate identification when we use algae as environmental indicators. In this study, we attempted taxonomical investigation of Navicula salinarum Grunow which is indicator diatom of water containing salt. This taxon is recorded including 11 infraspecific taxa. We examined each taxon in detail and following 4 taxa, Navicula salinarum Grunow var.salinarum f.salinarum, Nav. salinarum Grunow var. salinarum f.minima Kolbe, Nav. salinarum Grunow var. nipponica Skvortsov, Nav. salinarum Grunow var. rostrata (Hust.) Lange-Bert. are considered to be infraspecific taxa. In addition, Navicula salinarum Grunow var. gracilior Lacsny is recognized as new rank, Navicula gracilior H. Fukush., Kimura & Ts. Kobay. stat nov. judging from a morphology of the valve.
