This is a Jackson China restaurant ware oval plate or platter with a green scroll stencil pattern on the rim. The plate is 11 1/2" long and 9 1/4" wide. The backstamp reads Jackson China Falls Creek, PA. Several china manufacturers produced green scroll rim patterns with slight variations. I have a lot of other green rim pieces being listed that coordinate well but don't necessarily match.
Jackson China Restaurant Ware Green Scroll Rim Oval Platter Plate 11 IN