Pinnularia Parvulissima Guide
Credit: Aneliya Sakaeva
  1. Apices broadly rostrate to subcapitate
  2. Fascia present
  3. Proximal raphe ends closely placed
  4. Striae radiate in middle of valve
  5. Striae slightly convergent near apices

Pinnularia parvulissima has broadly rounded, subcapitate ends. The central area is large with a broad, rhombic fascia. The fascia is variable in width in different specimens. The raphe is lateral. The proximal raphe ends are small and closely placed.