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Epithemia adnata

(Kütz.) Bréb. 1838      Category: Epithemioid
BASIONYM: Frustulia adnata Kütz. 1833

Envekadea vanlandinghamii


Epithemia argus

LM scalebar = 10 µm = 40 pixels.


Contributor: Rex Lowe - December 2010
Length Range: 32-70 µm
Width Range: 7.5-9.7 µm
Striae in 10 µm: 12-14


Valves are dorsiventral and are 32-70 μm long and 7.5-9.7 μm wide. Valves taper toward rounded to rostrate ends. Striae are 12-14 in 10 μm and costae are 4-5 in 10 μm. There are 3-7 striae between costae. The dorsal margin is strongly convex and the ventral margin is moderately concave. The raphe canal lies against the ventral margin at distal ends of the valve and arches toward the dorsal margin in the valve center. The central arch of the canal is approximately 3-6 μm above the ventral margin reaching less than half the distance to the dorsal margin.

Original Description

Basionym: Frustulia adnata
Author: Kütz. 1833
Length Range: µm
Striae in 10 µm:

Original Description

Frustulis adnatis fuscis crassiusculis cymbiformibus opacis, saepe hyalino-marginatis, media interdum fascia transversali hyalina notatis, utrinque truncatis, plerumque binatim conjunctis.

Original Images

Cite This Page:
Lowe, R. (2010). Epithemia adnata. In Diatoms of the United States. Retrieved May 25, 2018, from

Species: Epithemia adnata

Contributor: Rex Lowe

Reviewer: Sarah Spaulding


Brébisson, A. de. (1838). Considérations sur les Diatomées et essai d’une classification des genres et des espèces appartenant à cette famille. Brée l'Ainé Imprimeur-Libraire, Falaise. 22 pp.

Krammer, K. and Lange-Bertalot, H. (1988). Bacillariophyceae. 2. Teil: Bacillariaceae, Epithemiaceae, Surirellaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Susswasserflora von Mitteleuropa, Band 2/2. Gustav Fisher Verlag, Jena.

Kützing, F.T. (1833). Synopsis Diatomacearum oder Versuch einer systematischen Zusammenstellung der Diatomeen. Linnaea 8(5): 529-620, pls. XIII-XIX.

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

Epithemia adnata CAS

North American Diatom Ecological Database (NADED)

NADED ID: 32003

Autecology Discussion

This taxon is often in aggregates in areas of low N/P ratio. Often epiphytic. Like other species of Epithemia, E. adnata contains endosymbiotic N-fixing cyanobacteria.

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

Epithemia adnata

EMAP Response Plots

Epithemia adnata

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.