Pseudostaurosira microstriata guide
  1. Valves small
  2. Striae short, composed of a single areola
  3. Valves vary from lanceolate to rhombic
  4. Spines marginal, in line with striae

Valves with linear to rounded to rhombic margins. Striae are limited to valve margin and composed of a single areola on the valve face and a second areola on the mantle. A spine is in line with each stria at the valve face margin.