Brachysira styriaca

(Grunow) R.Ross in B.Hartley 1986      Category: Symmetrical biraphid
BASIONYM: Navicula styriaca Grunow in Van Heurck 1880
SYNONYM(S): Anomoeoneis styriaca (Grunow) Hust. 1930 
REPORTED AS: Anomoeoneis styriaca (Patrick and Reimer 1966, p. 382, plate 33, fig. 15) 

Brachysira serians


Brachysira vitrea

LM scalebar = 10 µm = 80 pixels.


Contributor: Loren Bahls - March 2014
Length Range: 16-37 µm
Width Range: 4.9-7.1 µm
Striae in 10 µm: 26-30


Valves are lanceolate with rounded, unprotracted apices. The axial area is narrow. The central area is elliptical, apically elongated, with a middle constriction in larger valves. Proximal raphe ends are weakly expanded and close in small valves, becoming increasingly distant in larger valves. Striae are radiate. Areolae are transapically elliptic near the axial area and bacilliform towards the valve margins. Areolae are irregularly spaced, creating a pattern of undulating longitudinal lines.

Original Description

Basionym: Navicula styriaca
Author: Grunow in Van Heurck 1880
Length Range: µm
Striae in 10 µm:

Original Description

Original Images

Cite This Page:
Bahls, L. (2014). Brachysira styriaca. In Diatoms of the United States. Retrieved April 26, 2018, from

Species: Brachysira styriaca

Contributor: Loren Bahls

Reviewer: Marina Potapova


Camburn, K.E. and Charles, D.F. (2000). Diatoms of Low-Alkalinity Lakes in the Northeastern United States. Academy of Natural Sciences of Philadelphia, Special Publication 18, 152 pp.

Hartley, B. (1986). A check-list of the freshwater, brackish and marine diatoms of the British Isles and adjoining coastal waters. Journal of the Marine Biological Association of the United Kingdom 66: 531-610.

Lange-Bertalot, H. and Moser, G. (1994). Brachysira Monographie der Gattung. Bibliotheca Diatomologica 29: 1-212.

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.

Siver, P.A., Hamilton, P.B., Stachura-Suchoples, K. and Kociolek, J.P. (2005). Diatoms of North America. The Freshwater Flora of Cape Cod. Iconographia Diatomologica 14: 1-463.

Van Heurck, H. (1880). Synopsis des Diatomées de Belgique. Atlas. Ducaju & Cie., Anvers.

Links & ID's

Index Nominum Algarum (INA)

Transfer INA

California Academy of Sciences (CAS)

Brachysira styriaca CAS

North American Diatom Ecological Database (NADED)

NADED ID: 18019

Autecology Discussion

Specimens of B. styriaca pictured on this website are from Bent Flat Fen and Johns Lake, both in Flathead County, northwest Montana. The pH of Bent Flat Fen is 7.40 and specific conductance is 460 µS/cm. The pH of Johns Lake is 7.24 and specific conductance is 30 µS/cm. Lange-Bertalot & Moser (1994) report that B. styriaca is widely distributed and locally abundant in northern and alpine regions of the Northern Hemisphere and that it is a good indicator of oligotrophic and oligosaprobic waters.


Johns Lake, Glacier National Park, Montana: home of Brachysira styriaca.


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

Brachysira styriaca

EMAP Response Plots

Brachysira styriaca

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.