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Diatoms of the United States is now known as Diatoms of North America.
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Kützing 1833      Category: Asymmetrical biraphid
TYPE SPECIES: Encyonema paradoxum Kützing




Image Credit: Sarah Spaulding, Friedel Hinz

CLASS: Bacillariophyceae
  ORDER: Cymbellales
    FAMILY: Cymbellaceae

  1. Dorsal margin highly arched
  2. Ventral margin straight or nearly straight
  3. Stigmoids present or absent, if present then located on the dorsal central area
  4. Distal raphe ends ventrally deflected

Encyonema frustules are asymmetrical to the apical axis and symmetrical to the transapical axis. The dorsal margin is highly arched, while the ventral margin in straight or nearly straight. Stigmoids may be present or absent. If a stigmoid is present, it is located on the dorsal side of the central area. Distal raphe ends are ventrally deflected, while distal raphe ends of Cymbella are dorsally deflected. Apical pore fields are absent.

Cells may grow as single cells, produce mucilaginous sheaths, or form colonies within mucilaginous tubes. Encyonema is broadly distributed across North America, primarily in benthic habitats.

Cite This Page:
Spaulding, S., and Edlund, M. (2008). Encyonema. In Diatoms of the United States. Retrieved May 22, 2018, from

Contributor: Sarah Spaulding | Mark Edlund - December 2008
Reviewer: Marina Potapova - May 2010