Meyer zoysiagrass is an improved strain of Zoysia japonica. It was selected from a population of plants grown from seed by the U.S.D.A. in 1941. It was evaluated by the U.S.D.A., U.S.G.A., and state universities and released jointly by the U.S.D.A. and U.S.G.A. in 1951. The selection was named in honor of Frank N. Meyer, a plant explorer for the U.S.D.A. who made the first collection of zoysiagrass seed in Korea in 1905.

Zoysia matrella was introduced into the U.S. in 1911 from Manilla. It is chiefly a tropical and subtropical grass, but can be grown as far north as Connecticut in the U.S. Zoysia matrella grows well in moderate shade and forms a thick mat in full sun. The leaf blades of Zoysia matrella are narrow, sharply pointed and wiry. In tropical climates the grass remains green year around. But, in cooler climates it turns brown after several hard frosts and remains brown until late spring. Zoysia matrella must be propagated from sprigs and is quite slow to become established.

Emerald zoysiagrass is a hybrid between Zoysia japonica and Zoysia tenuifolia released by the U.S.D.A. and the Georgia Agricultural Experiment Station in 1955. Emerald combines the fine texture of Zoysia tenuifolia with the cold tolerance and faster rate of spread of Zoysia japonica. Emerald is similar to Zoysia matrella in appearance and habit.

Could one of those four. Google their names and see if one matches your lawn.

Hope it helps.