The Maryland shape was produced by the Edwin M. Knowles China Company from the mid-1920s until circa 1930. It was made in four different glazes; Old Rose - pink, Nile - green, Roma - yellow, and Ivory. All four glazes can be found on other shapes made at the same time, most notably Cameo and Marion.
When Maryland is found in the three colored glazes, it will be stamped with the glaze name and no other marking such as EMK's name or date code. The following comes from an undated catalog and describes the colored glazes used on Maryland:
Our contribution to colorful housewares. A fancy, heavily embossed shape with Old Rose glaze over an ivory body. A delightful three-tone color effect is brought out by the embossing, indentures and paneling.
Of all the glazes used on Maryland, green is the most difficult to find and Roma, or yellow, is almost always found with decals.
This shape is also made in the Yellow glaze which is known as Roma, and a new shade of Green, so very popular with the trade, which is called "Nile."