A Fanged Geranium is a magical flower with sharp teeth. Harry Potter received a minor bite from one during his O.W.L. exam for Herbology.
There is widespread historical speculation that the Muggle War of the Roses actually started with wizarding neighbours arguing over a Fanged Geranium.
Fanged Geraniums were mentioned in an advertisement for the Toots, Shoots 'n' Roots radio show that was printed in Rumours!. The ad copy asked, "Fanged Geranium nothing but gums?"
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