Planothidium frequentissimum var. minus (Schulz-Danzig) Lange-Bert. Planothidium frequentissimum var. minus (Schulz-Danzig) Lange-Bert. in Iconogr. Diatomol. 6: 276. 19991is new combination for Achnanthes lanceolata f. minor Schulz-Danzig21. (Basionym:) fig. 42, 2. Author abbreviation not checked.