Navicula germainii

J.H.Wallace 1960      Category: Symmetrical biraphid
SYNONYM(S): Navicula viridula var. germainii (J.H.Wallace) Lange-Bert. 

Navicula genovefae


Navicula geronimensis

LM scalebar = 10 µm = 80 pixels.


Contributor: Marina Potapova - February 2011
Length Range: 32-39 µm
Width Range: 7.0-8.3 µm
Striae in 10 µm: 13-15


Valves are lanceolate with drawn-out apices. The axial area is narrow and straight. The central area is slightly asymmetric and elliptical. The raphe is straight, with external proximal raphe ends slightly dilated and bent toward the primary side of the valve. The central nodule is asymmetrically expanded on the internal valve surface to the primary side. Terminal raphe fissures are hooked to the secondary valve side. Striae are radiate around the center, 13-15 in 10 µm, becoming parallel then convergent at the apices. The areolae are often visible under LM, ca. 30-32 in 10 μm.

Note that this concept of Navicula germainii follows that of Lange-Bertalot (2001), but differs from the original concept of Wallace (1960), who did not distinguish between N. germainii and N. rostellata sensu Lange-Bertalot. Patrick (Patrick and Reimer 1966) designated a lectotype specimen of Navicula germainii, but Patrick’s circle on holotype slide of N. germainii contains several specimens of both N. germainii and N. rostellata sensu Lange-Bertalot. The illustration of the lectotype in Patrick and Reimer (1966, Fig. 48:8) does not correspond to any of these specimens.

Original Description

Author: J.H.Wallace 1960
Length Range: 34-37 µm
Width Range: 7-9.5 µm
Striae in 10 µm: 13-14

Original Description

Valvis late lanceolatis 34-37 μ longis, 7-9.5 μ latis. Apicibus plus minus porrectis, subcapitatis, striis granulatis, centralibus radiantibus sed apices versus leviter convergentibus, 13-14 in 10 μ.

Original Images

Cite This Page:
Potapova, M. (2011). Navicula germainii . In Diatoms of the United States. Retrieved April 21, 2018, from

Species: Navicula germainii

Contributor: Marina Potapova

Reviewer: Sarah Spaulding


Lange-Bertalot, H. (2001). Navicula sensu stricto, 10 genera separated from Navicula sensu lato, Frustulia. Diatoms of Europe 2: 1-526.

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.

Wallace, J. (1960). New and variable diatoms. Notulae Naturae 331: 1-8.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Navicula germainii CAS

North American Diatom Ecological Database (NADED)

NADED ID: 46616

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

Navicula germainii

EMAP Response Plots

Navicula germainii

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.