This perfect flow blue mulberry butter pat is by the German company Utzschneider and Co, in the Bryonia pattern.
Measuring just 5 1/2" in diameter and under 1" tall, it is deeper than the average butter pat and could be used as a bread plate or dessert dish.
The black mulberry color is highlighted by thin lines of gold on the edges, high points and outlining the leaf pattern. This pattern was made by this company plus Villeroy and Boch in both a flow blue and mulberry--the pieces are often mixed together due to similarity in the backstamps.
There are a couple of firing stilt marks but no condition issues at all--this dish appears to have been rarely if ever used.
Petra Williams vol II dates this pattern to 1870 - 1891. Jeffrey Snyder dates it to 1860s - 1870s.
This cute little dish would make a lovely addition for a flow blue or mulberry collector.