Our lady's little glass (Grimm's Fairy Tale)

Once upon a time a waggoner's cart which was heavily laden with wine had stuck so fast that in spite of all that he could do, he could not get it to move again. Then it chanced that Our Lady just happened to come by that way, and when she perceived the poor man's distress, she said to him, "I am tired and thirsty, give me a glass of wine, and I will set thy cart free for thee." - "Willingly," answered the waggoner, "but I have no glass in which I can give thee the wine." Then Our Lady plucked a little white flower with red stripes, called field bindweed, which looks very like a glass, and gave it to the waggoner. He filled it with wine, and then Our Lady drank it, and in the self-same instant the cart was set free, and the waggoner could drive onwards. The little flower is still always called Our Lady's Little Glass.