Pinnularia diversa has rhombic-lanceolate valves without protracted apices. Pinnularia similiformis has a weakly undulate, lateral raphe and more distant proximal raphe ends.

LM scalebar = 10 µm
Length Range
28-46 µm
Width Range
5.0-7.0 µm
Striae in 10 µm
12-14
Pinnularia divergentissima LM6
Pinnularia divergentissima LM5
Pinnularia divergentissima LM4
Pinnularia divergentissima LM3
Pinnularia divergentissima LM2
Pinnularia divergentissima LM1
Pinnularia divergentissima LM6 Pinnularia divergentissima LM5 Pinnularia divergentissima LM4 Pinnularia divergentissima LM3 Pinnularia divergentissima LM2 Pinnularia divergentissima LM1

Also compare to

Pinnularia diversa

Østrup

Pinnularia similiformis

Krammer