Visit us at

Diatoms of the United States is now known as Diatoms of North America.
This site has been redesigned and updated, and will be closing soon.

Gomphonema pusillum

(Grunow) Kulikovskiy and Kociolek in Kulikovskiy et al. 2015      Category: Asymmetrical biraphid
BASIONYM: Gomphonema acuminatum var. pusilla Grunow in Van Heurck 1880
SYNONYM(S): Gomphonema montanum var. pumila (Grunow in Van Heurck) Temp. and H.Perag. 1908 
REPORTED AS: Gomphonema acuminatum var. pusillum (Thomas et al. 2009 Pl. 1 Figs 5-8) 

Gomphonema pseudosphaerophorum


Gomphonema pygmaeum

LM scalebar = 10 µm = 80 pixels.


Contributor: Pat Kociolek - September 2011
Length Range: 32-56 µm
Width Range: 6.5-9.0 µm
Striae in 10 µm: 11-13


Valves are linear-acute and biconstricted, with the broadest portion of the valve near the headpole. The center of the valve is slightly tumid and the headpole is acute. The axial area is straight with the central area barely differentiated and transverse. The raphe is lateral and undulate. Striae are punctate. Striae are radiate about the middle portion of the valve, becoming parallel to radiate towards the headpole and parallel to strongly radiate at the footpole. Striae at the central area are slightly more separate from the others. On one side of the central area a stria is reduced in length, on the other side the central stria terminates at the rounded stigma.

Original Description

Basionym: Gomphonema acuminatum var. pusilla
Author: Grunow in Van Heurck 1880
Length Range: µm
Striae in 10 µm:

Original Description

Original Images

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

Species: Gomphonema pusillum

Contributor: Pat Kociolek

Reviewer: Sam Rushforth


Kulikovskiy, M.S., Kociolek, J.P., Solak, C.N. and Kuznetsova, I. (2015). The diatom genus Gomphonema Ehrenberg in Lake Baikal. II. Revision of taxa from Gomphonema acuminatum and Gomphonema truncatum-capitatum complexes. Phytotaxa 233(3): 251-272. 10.11646/phytotaxa.233.3.3

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.

Reichardt, E. (1999). Zur Revision der Gattung Gomphonema: Die Arten um G. affine/insigne, G. angustatum/micropus, G. acuminatum sowie gomphonemoide Diatomeen aus dem Oberoligozän in Böhmen. Annotated Diatom Micrographs. Edited by Horst Lange-Bertalot. Iconographia Diatomologica, Volume 8, A.R.G. Gantner.

Thomas, E.W., Kociolek, J.P., Lowe, R.L. and Johansen, J.R. (2009). Taxonomy, ultrastructure and distribution of gomphonemoid diatoms (Bacillariophyceae) from Great Smoky Mountains National Park (U.S.A.). Nova Hedwigia, Beiheft 135: 201-237.

Van Heurck, H. (1880). Synopsis des Diatomées de Belgique. Atlas. Ducaju & Cie., Anvers.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)


Autecology Discussion


September 19, 2016 - Change in rank

This page was originally posted as Gomphonema acuminatum var. pusilla Grunow in Van Heurck. Based on the change in rank from variety to species by Kulikovskiy and Kociolek (Kulikovskiy et al. 2015), the taxon page was updated. Note that the transfer incorrectly states the basionym as G. acuminatum var. pusillium, rather than G. acuminatum var. pusilla. - S. Spaulding