Hygroptera Balfouriana Guide
Credit: Pat Kociolek
  1. Striae distinct
  2. Distal raphe ends subterminal
  3. Valves small

Valves broadly linear to nearly elliptical in outline. Raphe short, with the distal ends not reaching the apices. The proximal raphe ends terminate quite a distance from one another. Striae distinct and radiate.