Bahls 2013
Gomphonema parvulum is smaller (10–36 μm long) with less strongly radiate striae.
Gomphonema gracile lacks protracted apices and also has more weakly radiate striae.
Gomphonema mexicanum is larger and lacks the protracted headpole.
Grunow in Van Heurck 1880
Ehrenb. 1838
(Kütz.) Kütz. 1849