Staurosira Construens Binodis Guide
Credit: Eduardo Morales
  1. Valves bi-undulate
  2. Axial area linear to lanceolate
  3. Apical pore fields present
  4. Spines hollow

Valves at the larger end of the size range of S. construens var. binodis are bi-undulate, while smaller specimens are lanceolate to cruciform. The axial area is linear to slightly lanceolate. Two apical pore fields are present on the valve mantle. Under the SEM, the apical porefields are found to be composed of round poroids. Spines are hollow, spatulate and located between striae.