Kobayasialla Guide
Credit: Loren Bahls
  1. Striae radiate, may be crossed by longitudinal lines
  2. Striae very fine
  3. Axial area narrow
  4. Raphe straight, proximal raphe ends expanded

Kobayasiella valves are linear to linear-lanceolate, with ends rostrate or expanded and capitate. Because the striae often number more than 30 in 10 microns, they may not be visible in the light microscope. The striae are radiate in the center of the valve and become convergent at the valve apices. The raphe is filiform, with proximal raphe ends expanded. The raphe has fine, but distinctive 'kinks' or deflections at midvalve. Terminal raphe ends are strongly hooked.

Kobayasiella is found in low nutrient and acid waters, including peats of the northern hemisphere. As a group, this genus appears to be sensitive to anthropogenic influence, and negatively impacted by human activities. The genus contains the former Navicula subtilissima Cleve and its allies. Kobayasiella replaces the illegitimate genus Kobayasia Lange-Bertalot 1996.