Fanged Geraniums were magical flowers with sharp fangs, which could be harvested to use in cooking or potion-making to brew the Strength Potion and Skele-Gro. Seeds could be purchased from Dogweed and Deathcap or Bewildering Blooms.

As a seedling, the green leaves started filling out. These plants had to be well fed and fertilised, or the flowers would only have gums and no fangs. While teething, the flowers were prone to being particularly bitey.

The age of a flower was calculated by counting the rings on the fangs, and Hogwarts was known to have decades old Fanged Geraniums. Students at Hogwarts learnt about this plant in 5th year.