Pfitzer 1871      Category: Symmetrical biraphid
TYPE SPECIES: Plagiotropis baltica Pfitzer




Smallest to largest - 2 taxa sorted by maximum length

CLASS: Bacillariophyceae
  ORDER: Naviculales
    FAMILY: Plagiotropidaceae

  1. Valves lanceolate, poles narrow to pointed
  2. Valve face folded, forming prominent apical "lines" on either side of the raphe
  3. Raphe raised and positioned within a keel

The valve margins of Plagiotropis are lanceolate with narrow poles. The valve face is folded, with folds appearing as lines on either side of the raphe. The raphe itself is raised above the valve face and positioned within a keel. The axial area is narrow and the central area is variable in shape. Striae are parallel and composed of loculate areolae. In girdle view, cells appear constricted in the center.

Plagiotropis is an epipelic genus of brackish waters.

Cite This Page:
Spaulding, S., and Edlund, M. (2008). Plagiotropis. In Diatoms of the United States. Retrieved April 19, 2018, from

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