Pinnularia borealis var. lanceolata

Hust. in Schmidt et al. 1934      Category: Symmetrical biraphid

Pinnularia borealis


Pinnularia brebissonii

LM scalebar = 10 µm = 40 pixels.


Contributor: Loren Bahls - March 2014
Length Range: 28-57 µm
Width Range: 8.6-11.8 µm
Striae in 10 µm: 5-6


Valves are elliptic-lanceolate with convex margins. The apices are acutely rounded. The axial area is narrow. A large rounded central area is formed by one or two shorter striae on each side. Thre raphe is filiform and straight. Proximal raphe ends are slightly deflected to one side and tipped with expanded pores. Distal raphe ends are sickle-shaped. Striae are broad and widely separated, weakly radiate near the valve center and becoming convergent towards the apices.

Original Description

Author: Hust. 1934
Length Range: µm
Striae in 10 µm:

Original Description

Original Images

Cite This Page:
Bahls, L. (2014). Pinnularia borealis var. lanceolata. In Diatoms of the United States. Retrieved April 26, 2018, from

Species: Pinnularia borealis var. lanceolata

Contributor: Loren Bahls

Reviewer: Rex Lowe


Hustedt, F. (1943). Die Diatomeenflora einiger Hochgebirgsseen der Landschaft Davos in den schweizer Alpen. Internationale Revue der gesamten Hydrobiologie und Hydrographie 43:124-197, 225-280.

Krammer, K. (1992). Die Gattung Pinnularia in Bayern. Hoppea 52: 1-308.

Krammer, K. (2000). The genus Pinnularia. The Diatoms of Europe. Diatoms of Inland Waters and Comparable Habitats 1: 1-703.

Schmidt, A. (-). (1874-1959). Atlas der Diatomaceen-Kunde, von Adolf Schmidt, continued by Martin Schmidt, Friedrich Fricke, Heinrich Heiden, Otto Muller, Friedrich Hustedt. Reprint 1984, Koeltz Scientific Books, Konigstein, 480 plates.

Simonsen, R. (1987). Atlas and Catalogue of the Diatom Types of Friedrich Hustedt. J. Cramer, Berlin & Stuttgart 1: 525 pp.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Pinnularia borealis var. lanceolata CAS

North American Diatom Ecological Database (NADED)


Autecology Discussion

The specimens of P. borealis var. lanceolata pictured and described on this web page were collected in May 2007 from a shallow rainwater puddle on Stinkingwater Pass in Harney County, eastern Oregon (photo below).


Stinkingwater Pass, Harney County, eastern Oregon.

Credit/Source: Loren Bahls