Pinnularia Lata Guide
Credit: Loren Bahls
  1. Valves large, linear-elliptic
  2. Striae broad, coarse
  3. Axial area linear
  4. Apices obtusely rounded

Valves are large and linear-elliptic, 20-35 µm wide. Apices are obtusely rounded. The axial area is linear, about 1/3rd to 1/5th the valve width. The raphe is lateral and nearly straight. The broad, coarse striae number 3-4 in 10 µm.