PENNYROYAL
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].
Last modified 6-Dec-1997