SPEARMINT 571 



thol, 65 to 85 per cent; menthol combined as esters, 3 to 6 per cent; 

 and a body isomeric with borneol. 



MENTHA VIRIDIS. Spearmint. The leaves and flowering tops 

 of Mentha spicata (Syn. Mentha viridis), Fam. Labiatse, a perennial 

 herb (Fig. 240), indigenous to Europe and cultivated and naturalized 

 in various parts of North America. It should be collected in the same 

 manner as peppermint. 



Spearmint is extensively cultivated in Michigan and New York, 

 these States producing annually about 500 K. of volatile oil. 



Description. Closely resembling peppermint (see Mentha piper- 

 ita), but the stems are usually more purple, the leaves sessile or 

 nearly so, inflorescence either in slender, interrupted cylindrical 

 spikes or crowded lanceolate spikes (Fig. 240) ; odor and taste aro- 

 matic, characteristic, the taste not being followed by a cooling 

 sensation. 



Constituents. Volatile oil, about 0.3 per cent in the fresh leaves; 

 resin, and tannin. American oil of spearmint consists of about 56 

 per cent of carvone, a considerable amount of 1-limonene and'possibly 

 also 1-pinene. The constituent giving the oil its characteristic odor 

 is not known. 



Allied Plants. Russian spearmint oil is obtained from an unde- 

 termined plant and consists of 1-linalool, 50 to 60 per cent; 20 per 

 cent of cineol, 5 to 10 per cent of 1-carvone and possibly also 1-limonene. 



GERMAN SPEARMINT oil is obtained from Mentha crispa, which 

 is regarded as a cultural variety of M. arvensis. The plant is spar- 

 ingly naturalized in the United States from Europe. It somewhat 

 resembles M. piperita, but is distinguished by its cuspid, irregularly 

 dentate leaves. It yields an oil containing carvone. 



HEDEOMA. American Pennyroyal. The leaves and flowering 

 tops of Hedeoma pulegiodes (Fam. Labiatse), an annual herb indigen- 

 ous to the eastern and central United States and Canada. Penny- 

 royal should be collected in July or August and dried. 



Description. Stem quadrangular, 1 to 2 mm. in diameter, light 

 or reddish-brown, with numerous spreading hairs. Leaves elliptical 

 or ovate, opposite, 15 to 35 mm. in length, 5 to 14 mm. in breadth; 

 summit obtuse; base tapering into the petiole; margin remotely 

 serrate; upper surface dark green, pubescent on the nerves, slightly 

 glandular-hairy; under surface light green, pubescent, ' glandular- 

 hairy, veins of the first order diverging at an angle of 45 to 65, 

 curving upwards and uniting near the margin ; petiole 3 to 6 mm. in 

 length, with numerous spreading hairs and slightly laminate in the 

 upper portion. Inflorescence in six-flowered axillary whorls; calyx 



