Achnanthes lanceolata var. apiculata R.M.Patrick Achnanthes lanceolata var. apiculata R.M.Patrickis basionym for Planothidium apiculatum (R.M.Patrick) Lange-Bert. in Iconogr. Diatomol. 6: 274. 199911. (Basionym:) fig. 1: 4-5