DESCRIPTION.—Stem hairy; leaves 1/2 inch (12 mm.) long, short-petioled, oblongovate, slightly serrate; flowers in small axillary cymules, with small, pale blue, spotted, pubescent stamens; odor mint-like. Taste aromatic and pungent.
CONSTITUENTS.—Volatile oil containing hedeomol, C10H18O, and pulegone, C10H16O. The oil obtained from Mentha pulegium Linné has about the same specific gravity and optical rotation, and contains pulegone.
475 a. Oleum Hedoemae U.S. VIII—Oil of Pennyroyal.
A volatile oil distilled from the flowering plant of Hedeoma pulegioides Persoon.
SOURCE AND DESCRIPTION.—Most of the oil of pennyroyal is reported as being distilled in North Carolina and in the southern and eastern parts of Ohio.
It is a pale yellow liquid, having the characteristic odor and taste of Hedeoma. Its specific gravity is 0.920 to 0.935 at 25°C, It is soluble in 2 volumes of 70 per cent. alcohol forming a solution showing not more than a slightly acid reaction with litmus.
The principal and only constituent known definitely to exist in the oil is "pulegone," a ketone which can be identified by its hydrated oxime.
ACTION AND USES.—Oil of pennyroyal possesses stimulant, carminative, and emmenagogue properties.
The dose is from 2 to 10 minims (0.10 to 0.60 mil).
A Manual of Organic Materia Medica and Pharmacognosy, 1917, was written by Lucius E. Sayre, B.S. Ph. M.