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Stauroneis beeskovea

Bahls 2010      Category: Symmetrical biraphid

REPORTED AS: Stauroneis cf. gracilis (Metzeltin and Witkowski 1996) 

Stauroneis baconiana


Stauroneis bovbjergii

LM scalebar = 10 µm = 40 pixels.


Contributor: Loren Bahls - December 2011
Length Range: 93-137 µm
Width Range: 14-20 µm
Striae in 10 µm: 21-24


Valves are narrowly lanceolate with subtly protracted and broadly rounded apices. The axial area is narrow and linear, widening somewhat towards the central area. The stauros is a bit wider near the valve margins than at the center. One to three short striae are usually present on each side of the central area. Raphe fissures are lateral and the proximal ends are nearly straight. The proximal raphe pores are very small. Each raphe branch becomes filiform just short of the terminal fissures. Terminal raphe fissures are hooked towards the secondary side. The striae are radiate and strongly radiate near the apices. Areolae are fine and number 18-22 in 10 µm.

Original Description

Author: Bahls 2010
Length Range: 93-137 µm
Width Range: 14-20 µm
Striae in 10 µm: 21-24

Original Description

Valves narrowly lanceolate, ends subtly protracted and broadly rounded. Length 93-137 µm, width 14-20 µm. Length to width ratio: 6.5-7.7. Axial area narrow, linear, widening near the central area. Central area a narrow transverse fascia, widening slightly toward the valve margins. One to three shortened striae often present on each side. Raphe fissures lateral, proximal endings nearly straight, bent slightly toward the secondary side. Central pores very small, slightly inflated. Terminal raphe fissures hooked toward the secondary side. Striae radiate, quickly becoming very steeply radiate toward the ends, 21-24 in 10 µm. Striae puncta fine, 18-22 in 10 µm. For measurements, n = 24 valves.

Original Images

Cite This Page:
Bahls, L. (2011). Stauroneis beeskovea. In Diatoms of the United States. Retrieved May 23, 2018, from

Species: Stauroneis beeskovea

Contributor: Loren Bahls

Reviewer: Sarah Spaulding


Bahls, L. (2010). Stauroneis in the Northern Rockies: 50 species of Stauroneis sensu stricto from western Montana, northern Idaho, northeastern Washington and southwestern Alberta, including 16 species described as new. Northwest Diatoms, Volume 4. The Montana Diatom Collection, Helena, 172 pp.

Metzeltin, D. and Lange-Bertalot, H. (2002). Diatoms from the Island Continent Madagascar. In: Iconographia Diatomologica (Lange-Bertalot, ed.), Vol. 11, A.R.G. Gantner Verlag K.G., Ruggell., 286 pp.

Metzeltin, D. and Witkowski, A. (1996). Diatomeen der Baren-Insel Susswasser und marine Arten. In: Iconographia Diatomologica (H. Lange-Bertalot, ed.), Vol. 4, Koeltz Scientific Books, Konigstein, 287 pp.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Stauroneis beeskovea CAS

North American Diatom Ecological Database (NADED)


Autecology Discussion

Stauroneis beeskovea has been found in six small lakes in western Montana. In these waters pH ranges from 6.6 to 8.0 and specific conductance ranges from 10 to 67 µS/cm. Metzeltin & Witkowski (1996) published a photo of a similar and perhaps conspecific specimen from Bear Island in the North Atlantic (Stauroneis cf. gracilis Ehrenberg, Tafel 10, fig. 4, without diagnosis).


Beeskove Lake (right), Rattlesnake Wilderness, Missoula County, Montana: type locality of Stauroneis beeskovea.

Credit/Source: Google Earth