Encyonema Guide2
  1. Dorsal margin arched
  2. Distal raphe ends ventrally deflected
  3. Stigmoids present or absent

Encyonema frustules are asymmetric to the apical axis and symmetric to the transapical axis. The dorsal margin is highly arched, while the ventral margin is straight or nearly straight. Distal raphe ends are ventrally deflected. 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. 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.