Interesting facts

In the Mediterranean the plant was associated with Mercury, the god of healing, hence both its common and its scientific name. The north Teutons also valued Dog's Mercury highly and dedicated it to the Norse god Wotan/Odin. In the Middle Ages Dog's Mercury was used in witches' ointments. According to an old formulation, these contained the following nine herbs: poppy, vervain, mercury, houseleek, wall rue, heliotrop, dog's mercury, deadly nightshade and monkshood.

A further special feature is the color behavior of Dog's Mercury. The constituent hermidine is converted into a blue, red or brown dye, depending on how it is processed. While its elimination colors the urine red, the plant parts turn blue when dried. On account of this deep blue color, Dog's Mercury was also regarded as indigo in the past. Dog's Mercury also develops a slightly unpleasant odor on drying.