At the small end of the size range, N. innominata, N. soratensis and N. inconspicua may be difficult to distinguish. Nitzschia soratensis is more elliptic, areolae may be visible in LM and the striae are arched near the apices. Nitzschia inconspicua has more apiculate ends. Nitzschia fonticuloides has fine striae and subrostrate apices. Nitzschia frustulum has linear valves, with parallel parallel to lanceolate margins. The apices of N. frustulum are pointed to narrowly rounded.

LM scalebar = 10 µm
Innominata 009 Innominata 004Tif Innominata 003 Innominata 002 Innominata 006 Innominata 008
Length Range
6-14 µm
Width Range
2-3 µm
Striae in 10 µm

Nitzschia soratensis

Morales and Vis 2007

Nitzschia soratensis LM5 Nitzschia soratensis LM1 Nitzschia soratensis LM2 Nitzschia soratensis LM6 Nitzschia soratensis LM3 Nitzschia soratensis LM4
Length Range
3-17 µm
Width Range
2.0-3.3 µm
Striae in 10 µm

Nitzschia fonticoloides

Sovereign 1958

Fonticuloides 002 Fonticuloides 003 Fonticuloides 001 Fonticuloides 004B Fonticuloides 004
Length Range
9-16 µm
Width Range
3-4 µm
Striae in 10 µm

Also compare to

Nitzschia inconspicua


Nitzschia frustulum

(Kütz.) Grunow in Cleve and Grunow

BioData Reference
Krammer and Lange-Bertalot 2/2 Pl 68 Fig 1-8