Family: Lamiaceae (Labiatae), Hedeoma pulegioides (L.) Pers. and Mentha pulegium L.

Source: Simon, J.E., A.F. Chadwick and L.E. Craker. 1984. Herbs: An Indexed Bibliography. 1971-1980. The Scientific Literature on Selected Herbs, and Aromatic and Medicinal Plants of the Temperate Zone. Archon Books, 770 pp., Hamden, CT.

Pennyroyal represents plants of two genera, Mentha pulegium L., European pennyroyal, and Hedeoma pulegioides (L.) Pers., American pennyroyal. European pennyroyal is a low, prostrate, and spreading perennial herb, native to Europe and western Asia. Reaching a height of 0.3 meters, the plant has ovate to nearly orbicular leaves and lilac flowers. American pennyroyal is a low-growing annual plant, native to the eastern part of the United States. Reaching a height of 0.3 meters, the plant has multibranched pubescent stems, small, narrow, elliptic leaves, and light blue to purple flowers that appear in the summer months.

The reported life zone of European pennyroyal is 7 to 26 degrees centigrade with an annual precipitation of 0.3 to 1.2 meters and a soil pH of 4.8 to 8.3 (4.1-31). The plant is found in humid, low-coastal regions along the Mediterranean Sea, and grows best in fertile, moist soils with partial shade (14.1-8). American pennyroyal grows on dry, sandy soils and is commercially cultivated to only a very limited extent.

The essential oil of pennyroyal is obtained by steam distillation from leaves and flowering tops. The oil consists chiefly of pulegone but also contains menthone, isomenthone, l--pinene, l-limonene, dipentene, menthol, and other compounds (14.1-35). American pennyroyal has a similar essential oil. Other chemical constituents include bitter principle and tannin (14.1-35).

The leaves of pennyroyal have a strong mint-like odor and are used fresh or dried in culinary preparations, especially puddings from which it derives the name 'pudding grass.' The essential oil is used as a fragrance in cosmetics. Pulegone from the essential oil is used as a starting material for the manufacture of synthetic menthol.

As a medicinal plant, pennyroyal has traditionally been used as an antispasmodic, carminative, diaphoretic, emmenagogue, sedative, stimulant, aromatic, and stomachic. It has been used to promote menstruation, induce abortion, cure headaches, and relieve colds (11.1-101). The essential oil can be toxic, causing nausea, vomiting, diarrhea, depression, stimulation, and convulsions (8.2-19, 11.1-136). Pennyroyal is pharmaceutically classified as a diaphoretic and emmenagogue (14.1-35). The plant has been used as an insect repellent against fleas and other pests. Plants and oil can cause contact dermatitis (11.1-96).

European and American pennyroyal are generally recognized as safe for human consumption (21 CFR section 172.50 [l982]).

[Note: References listed above in parentheses can be found in full in the original reference].

Aromatic and Medicinal Plants Index

Last modified 6-Dec-1997