M.H.Hohn and Hellerman 1963
Valves of G. apicatum are much larger.
Gomphonema parvulum has straight, parallel striae.
Gomphonema exilissimum has a gradually attenuated and acutely rounded headpole.
Ehrenb. 1854
Kutz. 1849
(Grunow) Lange-Bert. and Reichardt 1996