Psammothidium lacustre

Enache and Potapova 2013      Category: Monoraphid

Psammothidium helveticum


Psammothidium lauenburgianum

LM scalebar = 10 µm = 80 pixels.


Contributor: Marina Potapova - March 2014
Length Range: 17-28 µm
Width Range: 8.4-11.2 µm
Striae in 10 µm: 22–26


Valves are lanceolate. The raphe valve has a linear axial area and a rectangular central area, occupying ½ to 2/3 of the valve breadth. The proximal raphe ends are slightly deflected internally. The terminal raphe fissures are long and deflected in opposite directions. The rapheless valve has a narrow axial area and round central area occupying 2/3 of the valve breadth. Striae are radiate. Areolae are 40–60 in 10 μm, with external round foramina, and internal expressions elongated transapically.

Original Description

Author: Enache and Potapova 2013
Length Range: 16.7-28 µm
Width Range: 8.4-11.2 µm
Striae in 10 µm: 22-26

Original Description

Original Images

Cite This Page:
Potapova, M. (2014). Psammothidium lacustre. In Diatoms of the United States. Retrieved April 21, 2018, from

Species: Psammothidium lacustre

Contributor: Marina Potapova

Reviewer: Sarah Spaulding


Enache, M.D., Potapova, M. Sheibley, R. and Moran, P. (2013). Three new Psammothidium species from lakes of Olympic and Cascade Mountains in Washington State, USA. Phytotaxa 127: 49-57. 10.11646/phytotaxa.127.1.8

Sheibley, R.W., Enache, M., Swarzenski, P.W., Moran, P.W. and Foreman, J.R. (2014). Nitrogen deposition effects on diatom communities in lakes from three national parks in Washington state. Water, Air, and Soil Pollution 225: 1857. 10.1007/s11270-013-1857-x

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)


Autecology Discussion

So far, Psammothidium lacustre has been found only in oligotrophic lakes of the Washington Cascade mountain range.