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Guide to Planothidium potapovae

C.E.Wetzel and Ector 2019

Planothidium Rostratum Guide
Credit: Marina Potapova
  1. Valves lanceolate-elliptic with rostrate or narrowly subcapitate apices
  2. Valves 5.0-6.0 μm wide
  3. Rapheless valve with a cavum
  4. Axial area on rapheless valve from narrow linear to expanded in the center
  5. Central area on raphe valve transeversely rectangular

Valves are lanceolate-elliptic with rostrate or narrowly subcapitate apices, 11.0-17.5 μm long, 5.0-6.0 μm wide. The rapheless valve has a linear axial area, which widens in the center. The central area on the rapheless valve is asymmetric and contains a cavum. The central area on raphe valve is wide, and transversely rectangular.