Grunowia solgensis

Valves are small and lanceolate. Larger valves have protracted apices, which can be recurved dorsally. Striae are weakly radiate. Areolae are coarse and irregularly spaced, particularly near the apical axis. Fibulae are coarse and extend approximately to the apical axis, numbering 6-7 in 10 µm.

This taxon is often reported as Nitzschia sinuata var. delognei (e.g. Krammer and Lange-Bertalot 1988; Potapova and Charles 2003, Morales and Vis 2007), and is considered to be closely related to other taxa in the Nitzschia sinuata group, including N. sinuata var. sinuata and N. sinuata var. tabellaria. However, upon closer ultrastructural examination under SEM, Kobayasi and Kobori (1990) determined that N. sinuata var. delognei differs considerably from the nominate variety, most prominently in terms of areolar occlusion (N. sinuata var. delognei has them, N. sinuata does not). This difference was used to argue that N. sinuata var. delognei should not be considered a variety within the N. sinuata, but rather separated and raised to the rank of species. Cleve-Euler was the first to recognize this taxon at the specific rank and used the specific epithet "solgensis" because an "N. delognei" already existed at the time of publication.