Botanical atlas
American Pennyroyal
Hedeoma pulegioides
This plant is kept in the atlas for identification and safety, not for use. Read the safety notes below before handling it, and keep it away from children, cats, and food.
American pennyroyal grew up alongside colonial cabins and along dry New England roadsides, and settlers quickly noticed what Native peoples of the region already knew: its crushed, pungent leaves kept fleas, mosquitoes, and gnats at bay. Bundles of the dried herb were hung in doorways and rubbed on skin and clothing through buggy summer evenings, and it earned a place in almost every old dooryard garden for exactly this purpose. It also carried a long, troubled history as a folk remedy for bringing on delayed menstruation, a use now understood to be dangerous rather than gentle. Today it survives mostly as a fragrant curiosity in herb gardens and a name in old household manuals, valued for its scent and history rather than for anything taken by mouth.
Safety.
American pennyroyal contains pulegone, which is toxic to the liver even in small amounts. Ingesting the leaf, its tea, or especially its essential oil has caused severe liver failure, seizures, and death, including from historical misuse as an abortifacient. Do not ingest any part of this plant or its oil; keep it away from pregnant women, children, and pets, as the essential oil is a known cause of poisoning in cats and dogs.
Our sister app HerbLens identifies american pennyroyal from a photo and keeps its full botanical portrait: growing guide, harvest notes, and look-alike warnings.
View on HerbLensHerbSense shares traditional herbal knowledge for education, not diagnosis or treatment. Herbs can interact with medicines and conditions. Speak with your doctor before acting on anything here, and seek care promptly for anything severe, sudden, or worsening.