This taxon has a long and narrow valve that usually appears sinuous. The pseudoraphe is very narrow. The central area is longer than it is broad. The straie are parallel (Patrick and Reimer 1966).
Synonyms
Synedra acus var. angustissima (Grun.) V. H., Syn. Diat. Belgique, p. 151. 1885 (Patrick and Reimer 1966.