Gomphonema Stoermeri Guide
Credit: Pat Kociolek
  1. Valves linear-lanceolate to clavate
  2. Central area asymmetric
  3. Stigma distinct

Valves are linear-lanceolate to clavate. The axial area is lanceolate. The central area is slightly asymmetric and smaller on the side bearing the stigma. Striae are parallel to radiate at the center and near the headpole, becoming more strongly radiate at the footpole.