Neidium fogedii

L.L.Bahls 2013      Category: Symmetrical biraphid
BASIONYM: Neidium kozlowi var. densestriata Foged 1981

REPORTED AS: Neidium kozlowi var. densestriata (Antoniades et al. 2008, p.201, plate 124, figs. 6-7, 9) 

Neidium bobmarshallensis


Neidium sacoense

LM scalebar = 10 µm = 40 pixels.


Contributor: Loren Bahls - April 2013
Length Range: 33-55 µm
Width Range: 9.3-11.1 µm
Striae in 10 µm: 17-18


Valves are lanceolate to linear-lanceolate, with subrostrate to subcapitate apices. A longitudinal line is evident along each margin. The axial area is narrow and widens near to the central area. The central area is wide, rectangular and asymmetric, oriented diagonally to the apical axis. Short striae are present at the margins of the central area. The raphe is lateral, becoming filiform near the proximal ends. The proximal raphe ends are hooked and recurved in opposite directions. Striae are oriented diagonally to the apical axis throughout. Areolae number 26-28 in 10 µm.

Original Description

Basionym: Neidium kozlowi var. densestriata
Author: Foged 1981
Length Range: 37 µm
Width Range: 9 µm
Striae in 10 µm: 18-20

Original Description

Valvis multo minoribus et striis densioribus a varietate nominata differt. Differs from the nominate variety by having much smaller valves and denser striae.

Original Images

Cite This Page:
Bahls, L. (2013). Neidium fogedii. In Diatoms of the United States. Retrieved April 25, 2018, from

Species: Neidium fogedii

Contributor: Loren Bahls

Reviewer: Sarah Spaulding


Antoniades, D., Hamilton, P.B., Douglas, M.S.V. and Smol, J.P. (2008). Diatoms of North America: The freshwater floras of Prince Petrcik, Ellef Ringnes and northern Ellesmere Islands from the Canadian Arctic Archipelago. Iconographia Diatomologica 17.

Bahls, L. (2013). New diatoms (Bacillariophyta) from western North America. Phytotaxa 82(1): 7-28.

Foged, N. (1981). Diatoms in Alaska. Bibliotheca Phycologica, Band 53, J. Cramer, Vaduz, 317 pp.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Neidium fogedii CAS

North American Diatom Ecological Database (NADED)


Autecology Discussion

Neidium fogedii is known from a lake in the Brooks Range of Alaska (Foged 1981), from surface waters in the Canadian High Arctic (Antoniades et al. 2008), and from a pond in the Rocky Mountains of Colorado (specimens shown on this web page). On the date the Colorado sample was collected, water temperature was 12.3 C, pH measured 7.20 and specific conductance measured 102 µS/cm. The Canadian specimens were collected from waters where pH varied between 8.1 and 8.5 and conductivity ranged from 151 to 707 (Antoniades et al. 2008).


One of many high elevation ponds at the Mexican Cut Nature Preserve in Gunnison County, Colorado: home of Neidium fogedii.

Credit/Source: Nature Conservancy