|Figure 8.American pennyroyal (Hedeoma pulegioides)|
Habitat and range.American pennyroyal is found in dry soil from Nova Scotia and Quebec to the Dakotas and southward.
Description.This strongly aromatic herb is of rather insignificant appearance, being a low-growing plant from 6 inches to a foot in height with a slender erect much-branched, somewhat hairy and square stem. The leaves are small, thin, and rather narrow. From July to September close flower clusters appear consisting of a few pale-bluish flowers. The entire herb has a strong mintlike odor and pungent taste.
Part used.The leaves and flowering tops are collected when the plant is in flower. The distillation of oil of pennyroyal is a limited industry carried on in scattered sections in the eastern part of the country.
Information on the extraction of volatile oils from plants is contained in the following publication:
Sievers, A.F. Methods of extracting volatile oils from plant material and the production of such oils in the United States. U.S. Dept. Agr. Tech. Bul. 16, 36 p. illus. 1928.