American Pennyroyal Oil

#### Pennyroyal Oil, American. The trade distinguishes between two types of pennyroyal oil. The so-called "American" penny-royal oil is steam distilled from the freshly harvested, slightly dried, flowering herb of **Hedeoma Pulegioides**. This is a small plant belonging to the same botanical order as peppermint, and it is a native of the eastern and midwestern United States. It is harvested in the midwest and regularly distilled, although the oil has a very limited application. **American Pennyroyal Oil **is a pale yellow, mobile oil with a fresh-herbaceous, strong and bitterminty odor, a rather thin body and a faintly woody dryout which varies according to the age of the oil. The taste is sharp, bitter and somewhat burning. American pennyroyal oil is occasionally used in industrial perfumes where great strength, masking power and low cost are called for. It blends well with rosemary oil, pine needle oils, lavandin oil, ocotea pretiosa, distilled citrus oils, methyl salicylate, lemongrass oil, citronella oil, dipentene, terpineol and similar materials which are often used in the above types of fragrance. The oil has found some use as an insect repellant in sprays and lotions. For a short while, the oil was used to some degree in the chemical industry as a starting material for the production of menthol. However, the so-called "European" pennyroyal oil is preferred for this purpose. The main constituent of the two oils, **Pulegone**, is easily transformed into **Menthol**** **(by reduction, a 70-year old synthesis), but this method is no longer the most popular way of producing "synthetic" menthol. In view of the above, it is conceivable the "American" pennyroyal oil may slowly disappear entirely from the market. See also **Pennyroyal**** ****Oil**** ****"Moroccan"**, next monograph.