A common name for a plant (Persicaria hydropiper), an herb with a biting, peppery taste historically used in medicine.
From Old English 'ars' (burning) + 'smart' (to sting or burn). The name refers to the plant's peppery, stinging sensation in the mouth when eaten, not to arsenic despite the spelling.
Despite its confusing name, arsesmart has nothing to do with arsenic—it was named for its sharp, spicy taste that makes your mouth 'smart' (sting), but the similar name caused folk to confuse it with actual poisons.
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