A Spode Stone China Dinner Plate measuring approximately 9.5 inches or 24.5 cms in diameter & decorated in a very simplified & stylised Imari design with gilt edged reserves containing 'trees' (Tree of Life?) with red berried fruit or flowers on a wide border band of cobalt blue further embellished with gilt swirls & smaller floral reserves.
This design does not look similar to any of Josiah Spode II's early Imari designs, the gilt swirls are particularly simple in their appearance. Spode's Stone China was introduced c1813 & this dinner plate is marked to its base with their special backstamp introduced with their product. This mark was used continuously until 1833 when the business changed ownership & became known as Copeland & Garrett. Spode also had a smaller, trimmed down version of this Stone China mark which they introduced a bit later around the 1815-1822 era probably for small items such as egg cups etc.
I have enquired with the Spode Museum Trust to see if they could locate the pattern number for this design but again this was a Spode design which was not known to them & unfortunately they were unable to find a record for it so if you have a piece of matching Spode Stone China with a pattern number on it both I & the Spode Museum Trust would be greatly interested to hear from you.
From the appearance of the design I suspect that this pattern dates to around the 1820's & probably falls into the pattern number range 3000 - 4000 but the smaller Dinner Plate size suggests an earlier pattern number around the 2000 range, so it is a bit of a mystery. Alternatively it may be a replacement piece for a Spode customer who had purchased a dinner service from another manufacturer.