Stauroneis acidoclinata

Lange-Bert. and Werum 2004      Category: Symmetrical biraphid

Stauroneis absaroka


Stauroneis acidoclinatopsis

LM scalebar = 10 µm = 40 pixels.


Contributor: Loren Bahls - December 2011
Length Range: 35-70 µm
Width Range: 7.4-11.5 µm
Striae in 10 µm: 19-24


Valves are linear-lanceolate to linear, with abruptly protracted subrostrate to subcapitate apices. External raphe fissures are weakly lateral. Proximal raphe ends are slightly curved and tipped with weakly expanded central pores. The axial area is narrow and linear, barely wider near the central area. The central area is a relatively broad stauros that is somewhat wider near the valve margins. Short striae are absent within in the stauros. Striae are weakly radiate near the center, becoming more strongly radiate toward the apices. Areolae are distinguishable in LM and number 20-30 in 10 µm.

Original Description

Author: Lange-Bert. and Werum 2004
Length Range: 35-60 µm
Width Range: 8.5-10.5 µm
Striae in 10 µm: 21-23

Original Description

Schalen linear-lanzettlich bis linear, Enden ziemlich abrupt keilformig verschmalert, meistens breit rostrat vorgezogen und breit gerundet, niemals capitat or subcapitat. Lange 35-60 microns, Breite 8.5-10.5 microns. Innere und aussere Raphenspalten (nicht stark) lateral, Zentralporen (im LM undeutlich) seitlich abgekrummt. Axialarea annahernd linear, weder eng noch breit, zur Mitte etwas erweitert. Zentralarea als Stauros bis zu den Randern ausgedehnt und nur wenig erweitert. Streifen im mittleren Schalenteil massig, zu den Enden hin stark radial, 21-23/10 microns. Punkte auf den Streifen (im REM) transapikal verlangert, ca. 25-30/10 microns.

Original Images

Cite This Page:
Bahls, L. (2011). Stauroneis acidoclinata. In Diatoms of the United States. Retrieved April 21, 2018, from

Species: Stauroneis acidoclinata

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.

Werum, M. and Lange-Bertalot, H. (2004). Diatoms in springs, from Central Europe and elsewhere under the influence of hydrogeology and anthropogenic impages. Iconographia Diatomologica 13: 1-417.

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

Stauroneis acidoclinata CAS

North American Diatom Ecological Database (NADED)

NADED ID: 62109

Autecology Discussion

Stauroneis acidoclinata has been recorded from several ponds and small lakes in western Montana, including Glacier National Park, where pH is circumneutral (mean pH = 6.8) and specific conductance is very low (mean SC = 35 µS/cm).


Bloody Dick Pond #1, Beaverhead County, Montana: home of Stauroneis acidoclinata.

Credit/Source: Loren Bahls