Basionym: Nitzschia turgidula Hustedt
Long narrow cells in stepped colonies or solitary. Valva linear, expanding towards the middle, with rounded apices. Cells slightly convex and ends truncate in girdle view. Raphe keel eccentric. Central nodulus present. Interstria with two rows of poroids (areolae).
Morphometrics: apical axis: 30-80 µm, transapical axis: 2.5-3.5 µm, 23-28 stria in 10 µm, 13-18 fibulae in 10 µm.
Distribution: Antarctic and Arctic