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Guide to Fragilariforma virescens

(Ralfs) D.M.Williams and Round 1988

Fragiliariaforma Virescens Guide
Credit: Eduardo Morales and Sarah Spaulding
  1. Valves linear to lanceolate, with rostrate ends
  2. Sternum narrow
  3. Rimoportulae one
  4. Spines present

Valves are linear to lanceolate with rostrate, broadly rounded ends. In girdle view, frustules are rectangular with undulate ends. Striae are composed of round areolae. Spines are positioned on the costae. Two distinct, simple porefields are present at each apex, located on the valve mantle near the junction with the valve face.