Nitzschia incognita

Legler and Krasske 1940      Category: Nitzschioid

Nitzschia fonticoloides


Nitzschia inconspicua

LM scalebar = 10 µm = 80 pixels.


Contributor: Loren Bahls - July 2016
Length Range: 19-48 µm
Width Range: 2.2-3.0 µm
Striae in 10 µm: 29-31


Valves are linear-lanceolate with narrow, acutely rounded apices. Fibulae on the eccentric keel number 11-15 in 10 µm. On most valves the two median fibulae are more widely spaced, giving the appearance of a “central nodule”. Striae are parallel and composed of indistinct areolae.

This taxon is very similar to and may be conspecific with Nitzschia radicula Hustedt.

Original Description

Author: Legler and Krasske 1940
Length Range: 34-52 µm
Width Range: 2 µm
Striae in 10 µm: 30

Original Description

Original Images

Cite This Page:
Bahls, L. (2016). Nitzschia incognita. In Diatoms of the United States. Retrieved April 22, 2018, from

Species: Nitzschia incognita

Contributor: Loren Bahls

Reviewer: Marina Potapova


Krammer, K. and Lange-Bertalot, H. (1988). Bacillariophyceae. 2. Teil: Bacillariaceae, Epithemiaceae, Surirellaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Susswasserflora von Mitteleuropa, Band 2/2. Gustav Fisher Verlag, Jena.

Lange-Bertalot, H., Kulbs, K., Lauser, T., Norpel-Schempp, M. and Willmann, M. (1996). Diatom taxa introduced by Georg Krasske: Documentation and revision. Iconographia Diatomologica (H. Lange-Bertalot, ed.), Vol. 3, Koeltz Scientific Books, Konigstein, 358 pp.

Legler, F. and Krasske, G. (1940). Diatomeen aus dem Vansee (Armenien). Beiträge zur Ökologie der Brackwasserdiatomeen. I. Bot. Centralbl. Beih. 60: 335-345.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Nitzschia incognita CAS

North American Diatom Ecological Database (NADED)

NADED ID: 48340

Autecology Discussion

The specimens pictured on this web page are from streams on the Northwestern Great Plains of Montana and from the Weiser River in northern Idaho. Krammer & Lange-Bertalot (1988) report this species from electrolyte-rich to brackish waters. It was originally described from a lake in Turkey and also reported from the North Sea Coast of Belgium. Nitzschia radicula is very similar to N. incognita, both in morphology and autecology.