Fagus undulata

About

Fagopsis is an extinct genus of beech relative in the family Fagaceae with two accepted species – Fagopsis longifolia and Fagopsis undulata. It has been found in fossil strata ranging in age between the Early Eocene to the Late Eocene or Early Oligocene in British Columbia, Colorado, Montana, and Washington. Several other species were formerly placed in the genus, but later removed because of insufficient associated fossils.

Summary from Wikipedia