Nitzschia Amphibia Guide
Credit: Pat Kociolek
  1. Valves are linear to lanceolate
  2. Striae distinctly punctate
  3. Central nodule present

Valves taper to bluntly rounded apices. Fibulae are distinct, 7-9 in 10 ┬Ám. The central nodule, evident as a wider space between two central fibulae, is present. Striae are characteristically prominent and distinctly punctate, and may be irregularly spaced.