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The striae of N. oregona are more coarsely punctate than those of N. romana. Nitzschia oregona is more slender and linear than N. perminuta.

LM scalebar = 10 µm
Nitzschia oregona LM1 Nitzschia oregona LM3 Nitzschia oregona LM2 Nitzschia oregona LM5 Nitzschia oregona LM4
Length Range
15-42 µm
Width Range
3 µm
Striae in 10 µm
23-25

Nitzschia perminuta

(Grunow in Van Heurck) H.Perag. 1903

Nitzschia perminuta LM1 Nitzschia perminuta LM5 Nitzschia perminuta LM4 Nitzschia perminuta LM3 Nitzschia perminuta LM2
Length Range
8-20 µm
Width Range
3-4 µm
Striae in 10 µm
22-27

Also compare to

Nitzschia romana

Grunow