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Psammothidium bioretii

(Germain) Bukht. and Round 1996      Category: Monoraphid
BASIONYM: Achnanthes bioreti Germain 1957
SYNONYM(S): Achnanthes biorettii Germain 

Psammothidium alpinum


Psammothidium chlidanos

LM scalebar = 10 µm = 80 pixels.


Contributor: Marina Potapova - August 2010
Length Range: 12-26 µm
Width Range: 5.3-9.1 µm
Striae in 10 µm: 23-27


Valves are elliptical. Both valves have narrow axial areas, which are often oblique to the apical axis and not parallel between the two valves. The central area is transversely elliptical or rectangular, bordered by 4-7 shortened striae of variable length. The raphe is straight or sigmoid near the apices, with slightly expanded terminal ends, but without terminal raphe fissures. The central raphe ends are simple or slightly expanded externally. Internally, the central raphe ends curve toward opposite sides. Striae are radiate through both valves and continue to the valve mantle, 23-27 in 10 µm in the middle and up to 30 in 10 µm at the apices. The external and internal openings of the areolae are circular, becoming transapically elongated toward the margins.

Original Description

Basionym: Achnanthes bioreti
Author: Germain 1957
Length Range: 18-20 µm
Width Range: 8-10 µm
Striae in 10 µm: 22-25

Original Description

Valva elliptica, apicibus largiter rotundatis (18-20 μm longa, 8-10 μm lata); striae omnes radiantes (22-25 in 10 μm) evidenter punctatae, aream longitudinalem angustam limitantes; area centralis secundum quadrilateram dilatata cum striis majoribus et minoribus alternatim; raphe evidenter obliquus secundum axem longitudinalem, pseudoraphe leviter obliquus.

Original Images

Cite This Page:
Potapova, M. (2010). Psammothidium bioretii. In Diatoms of the United States. Retrieved May 22, 2018, from

Species: Psammothidium bioretii

Contributor: Marina Potapova

Reviewer: Sarah Spaulding


Bukhtiyarova, L. and Round, F. E. (1996). Revision of the genus Achnanthes sensu lato. Psammothidium, a new genus based on Achnanthidium marginulatum. Diatom Research 11: 1-30. 10.1080/0269249X.1996.9705361

Germain, H. (1957). Achnanthes bioreti n. sp., diatomée nouvelle. Bulletin de la Société Botanique de France 104 (suppl.):85-86.

Manoylov, K.M. (2007). On some Psammothidium species from rivers in the United States. Diatom Research 22(2): 317–327.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Psammothidium bioretii CAS

North American Diatom Ecological Database (NADED)

NADED ID: 186001

Autecology Discussion

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

Psammothidium bioretii

EMAP Response Plots

Psammothidium bioretii

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.