Pinnularia Divergentissima Guide
Credit: Loren Bahls
  1. Striae with abrupt transition
  2. Valves linear to linear-lanceolate
  3. Apices subrostrate and obtusely rounded
  4. Raphe straight
  5. Proximal raphe ends closely spaced

Valves are striking in appearance because of the abrupt transition from extremely radiate to extremely convergent striae. Valves are linear to linear-lanceolate with subrostrate and obtusely-rounded apices. Raphe branches are filiform and the proximal raphe ends are small and close to one another.