The genus Nathorstia (ferns)

Nathorstia is a genus of Cretaceouslern with a broad distribution in the Northern Hemisphere. Previous authors have disagreed on the systematic position of Nathorstia, but investigation of the epidermis and sori of material from the lower Cretaceous of Primor'ye, Suyfun basin, has helped to clarify the problem. The genus was originally described by Heer, who assigned it to the family Marattiaceae, because of erroneous interpretation of the son. However, the true affinity is apparently with the Matoniaceae, particularly with the genus Phlebopteris Brongniart. A diagnosis of Nathorstia is presented, and N. pectinata (Goeppert) Krasilov, n. comb. (formerly Reussia pectinata Goeppert) is designated the type species. — S. H. Mamay.