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Guide to Psammothidium lauenburgianum

(Hust.) Bukht. and Round 1996

Psammothidium Lauenbergiana Guide
Credit: Paul Hamilton, Marina Potapova
  1. Valves are elliptic to elliptic-lanceolate
  2. Raphe straight
  3. Central area on raphe valve transversely rectangular to bow-tie shaped, symmetric or slightly asymmetric
  4. Central area on rapheless valve asymmetric, containing rimmed depression

Valves are elliptic to elliptic-lanceolate. The raphe valve has linear axial area and transversely rectangular to bow-tie shaped central area, which is slightly asymmetric or symmetric. The rapheless valve has a lanceolate axial area and a large, transverse, asymmetric central area with a rimmed depression on the internal valve surface. The striae are radiate on both valves.