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Guide to Planothidium apiculatum

(R.M.Patrick) Lange-Bert. 1999

Planothidium Apiculatum Guide
Credit: Marina Potapova
  1. Valves elliptic-lanceolate with apiculate apices
  2. Valves 9.0-12.7 μm wide
  3. Rapheless valve with a cavum

Valves are elliptic-lanceolate with apiculate apices. The raphe valve has a large rhomboid or transversely elliptic central area. The rapheless valve has an asymmetric central area, expanded at one side to the valve margin, containing a prominent cavum. The striae are strongly radiate on the raphe valve and slightly radiate on the rapheless valve.