Rabenhorst 1853      Category: Symmetrical biraphid
TYPE SPECIES: Frustulia saxonica Rabenhorst




Image Credit: Carrie Graeff

CLASS: Bacillariophyceae
  ORDER: Naviculales
    FAMILY: Amphipleuraceae

  1. Valve with distinct median longitudinal ribs
  2. Ribs form a single tip at valve ends
  3. Raphe present between longitudinal ribs
  4. Striae fine, punctate, forming transapical and longitudinal rows

Frustulia valves are rhomboid to linear-lanceolate with straight to undulate margins. The striae are composed of fine areolae, arranged into patterns that appear to form both apical and transapical rows.The genus possesses distinct median, longitudinal ribs that extend most of the length of the valve. The raphe is located between the longitudinal ribs. At the valve terminus, the ribs form a single tip, or porte-crayon. The proximal and distal raphe ends are not clearly observed with light microscopy. Living cells possess one H-shaped plastid.

Frustulia grows in benthic habitas as single cells or as colonies in mucilaginous tubes. Species of Frustulia are widespread in North America. Cells reach their greatest abundance in waters such as seepage lakes where water chemistry is slightly acidic, dissolved organic carbon (DOC) is high, and specific conductivity is relatively low.

Cite This Page:
Spaulding, S., and Edlund, M. (2008). Frustulia. In Diatoms of the United States. Retrieved April 20, 2018, from

Contributor: Sarah Spaulding | Mark Edlund - December 2008
Reviewer: Sam Rushforth - June 2010