Graeff, C.
(2011).
Frickea.
In Diatoms of North America.
Retrieved May 01, 2026, from https://diatoms.org/genera/frickea?x-craft-preview=409442409a997390693ff24c7010fd6f1c96fb56f8f091fa016a63de9a54aaccecpiqubknd
Symmetric Biraphid
Frickea
Distinct longitudinal ribs present
Ribs extend to the helictoglossa, but do not fuse
Rows of areolae present between ribs and raphe
Large, T-shaped distal raphe fissures
Large, T-shaped proximal raphe fissures
Species within Frickea have valves that are linear-lanceolate with bluntly rounded apices. The striae are comprised of relatively small, round areolae. Internally, a set of longitudinal ribs encloses the full length of the raphe and is continuous through the center of the valve. The longitudinal ribs extend to a linear helictoglossa but...