A great many people in the American Midwest have family roots in Germany, and a good number of them can tell you all about a beloved old-country holiday tradition: the Weihnachtsgurke, or Christmas Pickle.

They will tell you that an ornament in the shape of a pickle is always the last one hung on the tree on Christmas Eve, camouflaged somewhere among the pine needles. It might be shiny or matte; it might have gold swirls or a little Santa hat. But whatever the style, the story goes that the first child to find the pickle in the morning is assured of good luck in the coming year and a special gift.

It sounds plausible: Germans tend to love traditions, Christmas and pickles. Versions of the story and speculation over its origins proliferate on the internet. There is only one snag: It is all but unknown in Germany.

The YouGov polling agency surveyed 2,057 Germans in November and found that 91 percent had never even heard of this holiday legend attributed to their country.