All Taxa

Bacillariaceae: Bacillaria

Cells highly elongate, seen in valve or girdle view. Valves with shallow mantle, always lying in valve view, linear or linear-lanceolate, with pointed, rounded, cuneate to slightly rostrate poles.

Isopolar, isovalvar, and bilaterally ± symmetrical.

Striae transverse, parallel, uniseriate or biseriate, appearing in LM as simple lines.

Raphe central and slightly keeled, fibulate. Raphe sternum often with ridge on one side of raphe externally. Fibulae simple, rib-like, or linked longitudinally by ridges.

Girdle bands open. Usually two chloroplasts, one towards each pole. The central gap between them is where the nucleus lies.

Cells forming motile colonies, sometimes linked by interlocking ridges and grooves on the raphe-sternum, cells moving along each other.