Edlund, M.,
Burge, D.
(2015).
Pleurosigma.
In Diatoms of North America.
Retrieved May 01, 2026, from https://diatoms.org/genera/pleurosigma?x-craft-preview=cab8b13ef68d1e257235fd2491770f51dfe0c9a6c0ad3b95411776e5316d603alxhbyabypv
Symmetric Biraphid
Pleurosigma
Valves sigmoid
Raphe sigmoid
Striae decussate
Valves are elongate and sigmoid. Striae are composed of evenly spaced decussate rows. The rows are arranged in 3 patterns: a trans-apical row and two opposing oblique rows. Internally, the areolae are occluded by hymenes. The raphe is strongly sigmoid, with a narrow axial area. The sternum is thickened equally on both sides. The raphe...