Planothidium lanceolatum

(Bréb. ex Kütz.) Lange-Bert. 1999      Category: Monoraphid
BASIONYM: Achnanthidium lanceolatum Bréb. ex Kütz. 1846
SYNONYM(S): Achnanthes lanceolata (Bréb. ex Kütz.) Grunow in Van Heurck  

Planothidium holstii


Planothidium rostratum

LM scalebar = 10 µm = 80 pixels.


Contributor: Marina Potapova - December 2010
Length Range: 7-24 µm
Width Range: 4.5-8.0 µm
Striae in 10 µm: 12-15


Valves are lanceolate to elliptical-lanceolate with slightly drawn-out apices. The raphe valve has a linear axial area and central area that varies in shape - from transversely rectangular to elliptical. The rapheless valve has a linear-lanceolate axial area that slightly widens in the middle. The asymmetrical central area on the rapheless valve contains a rimmed depression on the internal valve surface.The raphe is straight with expanded external proximal endings. Terminal raphe fissures are curved to the secondary valve side. The striae are multiseriate and radiate throughout both valves.

Original Description

Basionym: Achnanthidium lanceolatum
Author: Bréb. ex Kütz. 1846
Length Range: 16 µm
Striae in 10 µm:

Original Description

A. a latere secundario elliptico – lanceolato; apicibus obtusis, rotundatis. — Long. 1/140”’.

Original Images

Cite This Page:
Potapova, M. (2010). Planothidium lanceolatum. In Diatoms of the United States. Retrieved April 23, 2018, from

Species: Planothidium lanceolatum

Contributor: Marina Potapova

Reviewer: Sarah Spaulding


Lange-Bertalot, H. (1999). Neue Kombinationen von taxa aus Achnanthes Bory (sensu lato). Iconographia Diatomologica 6: 276-289.

Van de Vijver, B., Wetzel, C., Kopalova, K., Zidarova, R. and Ector, L. (2013). Analysis of the type material of Achnanthidium lanceolatum Brébisson ex Kützing (Bacillariophyta) with the description of two new Planothidium species from the Antarctic Region. Fottea, Olomouc 13(2): 105–117.

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

Planothidium lanceolatum CAS

NCBI Genbank Taxonomy

Planothidium lanceolatum NCBI

North American Diatom Ecological Database (NADED)

NADED ID: 155003

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

Planothidium lanceolatum

EMAP Response Plots

Planothidium lanceolatum

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.