This has been one of my mystery items for some time. I have consulted many collectors, however, it may be an item made in the Ceramique Montoise Factory in Belgium. The colours do seem to match my other items from this Factory. The "hollow foot" may suggest a "Bergen" piece, even though the mountain mark is missing, which apparently disappeared after the late 1920s. The item seems to be of a good quality, in sharp contrast with the Bergen planter in my collection which is probably an earlier piece, since it has been suggested that the general quality improved after the mid 1920s.
(The above information was gratefully received from Ron Tasman.)