Compare

The taxon, G. chinense, a species described from China, is very similar to this species. Gomphonema chinense is more linear in valve outline. While some specimens of G. chinense have a rostrate to subcapitate headpole, only G. sierranum consistently has this headpole shape.

LM scalebar = 10 µm
Gomphonema sierranum LM2 Gomphonema sierranum LM7 Gomphonema sierranum LM4 Gomphonema sierranum LM1 Gomphonema sierranum LM3 Gomphonema sierranum LM5 Gomphonema sierranum LM6
Length Range
23.1-30.4 µm
Width Range
4.0-4.5 µm
Striae in 10 µm
12-15

Also compare to

Gomphonema chinense

Liu and Kociolek 2013