Psammothidium marginulatum

(Grunow) Bukhtiyarova and Round 199      Category: Monoraphid
BASIONYM: Achnanthes marginulata Grunow in Cleve and Grunow 1880

Psammothidium levanderi


Psammothidium nivale

LM scalebar = 10 µm = 80 pixels.


Contributor: Marina Potapova - August 2010
Length Range: 8-16 µm
Width Range: 4.4-5.8 µm
Striae in 10 µm: 23-27


Valves are elliptical-lanceolate to linear-elliptical. The raphe valve has a linear axial area, which widens toward the center of the valve, and a transversely elliptical central area. The raphe is straight, without terminal fissures. The central and terminal raphe ends are simple. The central raphe ends curve toward opposite sides internally. The rapheless valve has a wide rhomboid-lanceolate axial area. The central area is usually not differentiated from the axial area. Striae are radiate on both valves, 23-27 in 10 µm. One row of areolae is present on the mantle of both valves. The external openings of the areolae are small , circular.

Original Description

Basionym: Achnanthes marginulata
Author: Grunow in Cleve and Grunow 1880
Length Range: 11-14 µm
Width Range: 5 µm
Striae in 10 µm:

Original Description

Sehr klein, wenig gebogen. Schaalen oval oder fast stumpf lanzettlich. Die Querstreifen der Oberschaale kurz, randständig, die der Unterschaale radial, die Mittellinie erreichend, in der Mitte beim breiten Pseudostauros aber nur sehr kurz, randständig, 24-25 in 0,01 mm. Länge 0,011-0,014 mm., Breite 0,005 mm. Memerutungen. (Norwegen.) O. Nordstedt

Original Images

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

Species: Psammothidium marginulatum

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

Cleve, P.T. and Grunow, A. (1880). Beiträge zur Kenntniss der Arktischen Diatomeen. Kongliga Svenska-Vetenskaps Akademiens Handlingar, 17(2): 121 pp., 7 pls.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Psammothidium marginulatum CAS

North American Diatom Ecological Database (NADED)

NADED ID: 186005

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 marginulatum

EMAP Response Plots

Psammothidium marginulatum

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.