Delicata Guide3
  1. Valves slightly asymmetric to apical axis
  2. Terminal raphe fissures deflected to dorsal side
  3. Raphe lateral
  4. External expression of foramina variable

Valves are slightly asymmetric to the apical axis and symmetric to the transapical axis. The valve shape is narrow and lanceolate. The raphe is distinctly lateral and becomes reverse-lateral at the center of the valve. The proximal raphe ends are thin. The terminal raphe fissures are deflected toward the dorsal side. Valves lack a distinct central area. The striae are fine and usually number more than 18 in 10 ┬Ám. Within the striae, external expression of the foramina is variable; foramina may be oval, zig-zag, undulate or other shapes. Stigmata, stigmoids and apical pore fields are absent.

Delicata was segregated from Cymbella sensu lato (Krammer 2003). Species are distributed broadly, from the tropics to the subarctic.