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Diatoms of the United States is now known as Diatoms of North America.
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Gomphonema apicatum

Ehrenb. 1854      Category: Asymmetrical biraphid

Gomphonema americobtusatum


Gomphonema apuncto

LM scalebar = 10 µm = 40 pixels.


Contributor: Pat Kociolek - September 2011
Length Range: 40-53 µm
Width Range: 13-15 (as measured at the broadest portion of the valve) µm
Striae in 10 µm: 9-11


Valves are acuminate-apiculate, asymmetric to the transapical axis, with a rounded footpole. The axial area is straight, broadening transversely to form the central area. The raphe is lateral and undulate. The striae are punctate, radiate at the poles to nearly parallel in the middle of the valve. Striae in the central valve are more widely spaced than other striae. On one side of the central area a stria is shortened, on the other side the central stria terminates next to the single stigma.

Original Description

Author: Ehrenb. 1854
Length Range: µm
Striae in 10 µm:

Original Description

Original Images

Cite This Page:
Kociolek, P. (2011). Gomphonema apicatum. In Diatoms of the United States. Retrieved May 25, 2018, from

Species: Gomphonema apicatum

Contributor: Pat Kociolek

Reviewer: Rex Lowe


Ehrenberg, C.G. (1854). Mikrogeologie. Einundvierzig Tafeln mit über viertausend grossentheils colorirten Figuren, Gezeichnet vom Verfasser. Voss, Leipzig., Pl. 5, II, fig. 23 (iconotype).

Patrick, R.M. and Reimer, C.W. (1975). The Diatoms of the United States, exclusive of Alaska and Hawaii, V. 2. Monographs of the Academy of Natural Sciences of Philadelphia 13.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Gomphonema apicatum CAS

North American Diatom Ecological Database (NADED)


Autecology Discussion