Brachysira vitrea

(Grunow) R.Ross in B.Hartley 1986      Category: Symmetrical biraphid
BASIONYM: Gomphonema ? vitrea Grunow in O.Schneid. 1878
SYNONYM(S): Anomoeoneis vitrea (Grunow) R.Ross in R.M.Patrick and Reimer 1966 

Brachysira styriaca


Brachysira zellensis

LM scalebar = 10 µm = 80 pixels.


Contributor: Loren Bahls - March 2014
Length Range: 12-25 µm
Width Range: 4.3-5.9 µm
Striae in 10 µm: 32-36


Valves are broadly elliptic-lanceolate with capitate apices. The axial area is narrow. The central area is small and elliptic. The raphe is filiform and straight. Proximal raphe ends are weakly expanded. Distal raphe ends are indistinct in LM. Striae are radiate and uniseriate. Areolae in the striae are transapically elliptic to bacilliform. Areolae are irregularly spaced, creating a pattern of undulating longitudinal lines.

Note that Patrick and Reimer (1966) reported Brachysira microcephala as Anomoneis vitrea, in error. That reference was a source of confusion for many analysts. See also the Brachysira microcephala page.

Original Description

Basionym: Gomphonema ? vitrea
Author: Grunow in O.Schneid. 1878
Length Range: µm
Striae in 10 µm:

Original Description

Original Images

Cite This Page:
Bahls, L. (2014). Brachysira vitrea. In Diatoms of the United States. Retrieved April 22, 2018, from

Species: Brachysira vitrea

Contributor: Loren Bahls

Reviewer: Marina Potapova


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.

Schneider, O. (1878). Naturwissenschaftliche Beiträge zur Kenntniss der Kaukasusländer, auf Grund seiner Sammelbeute. Dresden. 160 pp. + 5 plates.

Links & ID's

Index Nominum Algarum (INA)

Transfer INA

California Academy of Sciences (CAS)

Brachysira vitrea CAS

North American Diatom Ecological Database (NADED)

NADED ID: 18006

Autecology Discussion

Specimens of B. vitrea pictured on this website were collected from the Cheyenne River in western South Dakota and from Connelly Fen on the Northwestern Great Plains in Montana (photo below). Connelly Fen, a shallow, highly calcareous fen, has a pH of 7.60 and a specific conductance of 1500 µS/cm. Common diatom associates of B. vitrea in Connelly Fen are Denticula kuetzingii, Denticula valida, Epithemia argus and species of Mastogloia. Lange-Bertalot & Moser (1994) report B. vitrea from chalk-rich lakes in Sweden and the southern Alps and describe it as a good indicator of oligosaprobic and oligotrophic chalk-rich waters.


Connelly Fen, Blackfeet Reservation, Glacier County, Montana: home of Brachysira vitrea.

Credit/Source: Peter Lesica

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 vitrea

EMAP Response Plots

Brachysira vitrea

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.