Hound's Tongue

Hound's tongue, or houndstongue, is a herbaceous plant of the borage family, found across most of Europe and in North America, where it arrived by accident. Wikipedia says it lives in wet places, sand dunes, waste land and hedges, may be pollinated by bees or pollinate itself, and is designated a noxious weed in British Columbia. It is also called houndstooth, dog's tongue, gypsy flower and, because of its smell, rats and mice. Cunningham adds the folk names dog-bur, sheep lice, tongue of dog and woolmat, and gives it a single use: placed in the shoe, it stops dogs barking at you, in effect tying their tongues. He calls it masculine, ruled by Mars and of the element fire. Wikipedia warns that the plant contains tumorigenic pyrrolizidine alkaloids, chemicals that can cause tumours, and that it is toxic to cows and especially dangerous to pasture owners.