Hedeoma pulegioides (L.) Pers. - syn. Melissa pulegioides L. - Lamiaceae
American (false) pennyroyal, Squaw mint, tickweed, Amerikanische Poleiminze, Flohkraut, Frauenminze
Annual herb, up to 50cm tall, native to eastern North America; aromatic peppermint-like smelling, much-branched; leaves small, thin, narrow; flowers pale blue.
„In the early 20th century, it was used in domestic medicine, in the form of a warm infusion, to promote perspiration and as an emmenagogue. Upon ingestion, one of its components, pulegone, metabolizes into hepatotoxic metabolites that depending on dosage can lead to organ failure, seizures, and death. In the 19th century it was recommended for flea control…“ https://en.wikipedia.org/wiki/Hedeoma_pulegioides
The herb (Herba Hedomae, Herba Pulegii americanae) was formerly used as antirheumatic and diaphoretic, but the essential oil is toxic, leading to unconsciousness, tremor and tetanic cramps. Essential oil: 0.6-1% (f.w.), 1,3-3% (d.w.) with α-pinene, limonene, pulegone, menthone, isomenthone, 3-methyl hexanone.
[Hagers Handbuch der Pharmazeutischen Praxis, Springer 2010]
Millspaugh, C.F., American medicinal plants, vol.2 t.118 (1892)