Gomphonema Incognitum Guide
Credit: Ian Bishop
  1. Valves broadly clavate
  2. Axial area wide
  3. Striae weakly radiate
  4. Stigmoid present

Valve outline is broadly clavate, with a rounded headpole. The striae are weakly radiate and uniseriate, becoming more radiate at the footpole. The axial area is broadly lanceolate. A stigmoid is located in the central area.