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Stauroneis smithii var. incisa

Pant. 1902      Category: Symmetrical biraphid
SYNONYM(S): Stauroneis smithii fo. incisa (Pant.) Hust. 1957 

Stauroneis smithii


Stauroneis sonyae

LM scalebar = 10 µm = 80 pixels.


Contributor: Ian Bishop - March 2016
Length Range: 19-37 µm
Width Range: 4.4-5.8 µm
Striae in 10 µm: 32-36


Valves are narrowly lanceolate, with subtle marginal undulation and apiculate apices. The axial area is narrow and linear. The raphe is filiform. Striae are fine and parallel throughout the valve. In many specimens, or in less than optimal illumination, striae may not be visible. Pseudoseptae are present at both apices and are visible at high and lower focal planes in LM. The stauros is robust and rectangular.

Original Description

Author: Pant. 1902
Length Range: 18.9 µm
Width Range: 5.4 µm
Striae in 10 µm: 33

Original Description

40. Stauroneis Smithii Grün, var incisa Pant. n. v. 

Valvis maxime convexis, 18’9 µ longis, 5’4 µ latis, late lanceolatis, acutis, medio valvae constrictis; rhaphe directa, stauro transverso dilatato; striis transversis, parallelis, 33 in 10 µ, usque ad apicem non percurrentibus, propter convexitatem valvae quasi pulvinulos quatuor constituentes. Seeschlamm : Siófok (tb. II, fig. 45).

Original Images

Cite This Page:
Bishop, I. (2016). Stauroneis smithii. In Diatoms of the United States. Retrieved May 23, 2018, from

Species: Stauroneis smithii

Contributor: Ian Bishop

Reviewer: Mark Edlund


Camburn, K. E. (1977). The haptobenthic diatom flora of Long Branch Creek, South Carolina . M.S. Thesis, Bowling Green State University, Bowling Green, Ohio, USA, 266 pp.

Levkov, Z., Tofilovska, S., Jovanovska, E., Cvetkoska, A. and Metzeltin, D. (2016). Revision of the Stauroneis smithii Grunow (Bacillariophyceae) species complex from Macedonia. Botanica Serbica 40(2): 167-178.

Pantocsek, J. (1902). Kieselalgen oder Bacillarien des Balaton. Resultate der Wissenschaftlichen Erforschung des Balatonsees, herausgegeben von der Balatonsee-Commission der Ung. Geographischen Gesellschaft. Commissionsverlag von Ed. Hölzel. Wien. 2(2): 112 pp., 17 pls.

Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.

Reimer, C.W. (1961). New and variable taxa of the diatom genera Anomoneis Pfitz. and Stauroneis Her. (Bacillariophyta) from the United States. Proc. Acad. Nat. Sci. Philadelphia 113: 187-214.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Stauroneis smithii var. incisa CAS

North American Diatom Ecological Database (NADED)

NADED ID: 62018

Autecology Discussion

In a 2013 US Geological Survey examination of wadeable streams in the southeastern US, Stauroneis smithii var. incisa was found to be rare (<1% of a 600 valve count) in more than 20 streams spanning Virginia, North Carolina, South Carolina, and Geogia. Camburn (1977), in his robust examination of diatom flora seasonality in Long Branch Creek, South Carolina, found this taxon to be mostly rare in counts, but occasionally common and even sometimes abundant. Camburn observed that S. smithii var. incisa was most abundant in late summer/early fall and that the species exhibited a preference for epilithic substrates, regardless of current.

EMAP Assessment

The Environmental Protection Agency (EPA) western Environmental Monitoring and Assessment Program (EMAP) study was completed during the years 2000-2004 (see citations at bottom of this page). Over 1200 streams and rivers in 12 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming) were selected for sampling based on a stratified randomized design. This type of design insures that ecological resources are sampled in proportion to their actual geographical presence. Stratified randomized design also allows for estimates of stream length with a known confidence in several “condition classes” (good or least-disturbed, intermediately-disturbed, and poor or most-disturbed) for biotic condition, chemistry and habitat.

EMAP Distribution

Stauroneis smithii var. incisa

EMAP Response Plots

Stauroneis smithii var. incisa

EMAP citations

Results are published in:

Johnson, T., Hermann, K., Spaulding, S., Beyea, B., Theel, C., Sada, R., Bollman, W., Bowman, J., Larsen, A., Vining, K., Ostermiller, J., Petersen, D. Hargett, E. and Zumberge, J. (2009). An ecological assessment of USEPA Region 8 streams and rivers. U.S. Environmental Protection Agency Region 8 Report, 178 p.

Stoddard, J. L., Peck, D. V., Olsen, A. R., Larsen, D. P., Van Sickle, J., Hawkins, C. P., Hughes, R. M., Whittier, T. R., Lomnicky, G. A., Herlihy, A. T., Kaufman, P. R., Peterson, S. A., Ringold, P. L., Paulsen, S. G., and Blair, R. (2005). Environmental Monitoring and Assessment Program (EMAP) western streams and rivers statistical summary. U.S. Environmental Protection Agency Report 620/R-05/006, 1,762 p.

Stoddard, J. L., Peck, D. V., Paulsen, S. G., Van Sickle, J., Hawkins, C. P., Herlihy, A. T., Hughes, R. M., Kaufman, P. R., Larsen, D. P., Lomnicky, G. A., Olsen, A. R., Peterson, S. A., Ringold, P. L., and Whittier, T. R. (2005). An ecological assessment of western streams and rivers. U.S. Environmental Protection Agency Report 620/R-05/005, 49 p.