Compare Gomphonema johnsonii
Gomphonema parvulum is smaller (10–36 μm long) with less strongly radiate striae.
Gomphonema gracile lacks protracted apices and also has more weakly radiate striae.
Gomphonema mexicanum is larger and lacks the protracted headpole.
LM scalebar = 10 µm
Length Range
24-50 µm
24-50 µm
Width Range
6.9-8.5 µm
6.9-8.5 µm
Striae in 10 µm
9-12 at the valve center, 14-18 near the apices
9-12 at the valve center, 14-18 near the apices
Length Range
26-55 µm
26-55 µm
Width Range
9-13 µm
9-13 µm
Striae in 10 µm
9-11
9-11
