Pseudostaurosira Americana Guide
Credit: Eduardo Morales, Barry Rosen and Sarah Spaulding
  1. Valves linear to elliptic
  2. Sternum narrow and linear
  3. Striae slightly alternate
  4. Spines aligned with striae

Valves are linear in large specimens, to nearly oval in smaller ones. The sternum is centrally placed and very narrow. Striae are punctate, uniseriate and slightly alternate (referring to how striae from opposite margins "meet" at the central sternum). Each spine is aligned with a stria.