LEAVES AND HERBS. 
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with numerous spreading hairs and slightly laminate 
in the upper portion. Inflorescence in six-flowered ax- 
illary whorls; calyx tubular, about 5 mm. long, ovoid 
or slightly curved on the lower side near the base, 
bilabiate, upper lip three-toothed, lower lip with two 
linear-lanceolate divisions, thirteen-nerved, longitudi- 
nally striate, pubescent; corolla about the size of the 
calyx, purplish, pubescent, upper lip erect, flat, emar- 
ginate, the lower spreading and three-lobed; fertile 
stamens two, exserted, ascending, the sterile upper pair 
rarely with anthers. Nutlets nearly spherical, about 
05 mm. in diameter. Odor strongly aromatic. Taste 
aromatic. 
Constituents. — Volatile oil about 1 per cent.; a 
bitter principle and tannin. 
Allied Plants. — Mentha Pulegium, or European pen- 
nyroyal, apparently contains principles similar to the 
American pennyroyal, and is distinguished from the 
latter by the more or less oval serrate leaves, and the 
cymose inflorescence with four-lobed corolla. 
MENTHA PIPERITA (Peppermint). 
The leaves and flowering tops of Mentha piperita 
(Earn. Labiate), a perennial herb indigenous to Europe, 
naturalized in the Eastern and Central United States 
and Canada, and cultivated in Michigan and New York. 
Peppermint should be collected during dry weather, in 
August and September, when the plant is in flower, 
and carefully dried and preserved. 
Description. — Stem quadrangular, 1 to 3 mm. in 
diameter, yellowish green, with scattered deflexed hairs, 
internodes 1'5 to 5 cm. long. Leaves ovate-lanceolate, 
opposite, L5 to 8 cm long, 05 to 2 - 5 cm. broad; apex 
acute; base acute or rounded; margin sharply serrate; 
upper surface dark green, midrib and veins rose-col- 
