Peppermint

(Mentha x piperita L., Labiatae)

There are thought to be around 30 different species of mint - but as the plants readily cross-pollinate and hybridise no-one is really certain. A number of different species of peppermint are recognised, differing in colour of leaves and of stems, also in aroma.

Description: The plant is a hybrid between M. aquatica and M. spicata.
A perennial herb spreading readily by means of subterranean and aerial stolons, stems 40-80cm (16-32in) high, square, unbranched in the lower part but much branched above.
Leaves somewhat variable according to the race; oblong to lanceolate, 4-8cm (1 •5-3in) long and 1.5-2.5cm (0.6-1 in) broad; green or reddish-green, margin deeply dentate.
Flowers about 8mm (0'3in) long with reddish-pink corolla, arranged in groups in the axils of bracts, often interrupted, in a terminal spike.

Peppermint is the variety most widely used in herbal medicine, and is believed to be a cross between spearmint (M. spicata) and water mint (M. oquotico): it has a high menthol content - hence the characteristic smell.
Until the 17th century there was little differentiation between the species - peppermint would just as often have been used in "mint sauce" as the apple mint (M. suoveolens) used today.
Spearmint, also known as common mint or garden mint, is the variety most often grown in gardens and makes an adequate substitute for peppermint used medicinally.
It does not have the high menthol content of peppermint, so is far less irritant and can be more suitable for children.

Part Used: Dried leaves; or generally the entire plant for domestic use and for distillation of the volatile oil.

Habitat and Cultivation: Native to Europe although not truly wild; commercially grown in the United States. Found in ditches and roadsides locally throughout Britain.
Cultivated by means of stolons 1 5x 30cm (6x 1 2in) apart in rich, light soil that is not too dry, (Seldom grown from seed, which produces only a small proportion of genuine pepper­mint.)
Two crops may be taken annually (in June-July and in autumn) after the plants have branched and flowered.
Drying is as rapid as possible in the shade at less than 35 C (95 F).
Yield: 10-25kg (22-551b) per are (120 sq yd).

Constituents and Action: A volatile oil containing menthol; tannin.
Peppermint is antiseptic, analgesic, anti-emetic, antispasmodic, carminative, bile stimulant, digestive tonic, peripheral vasodilator, diaphoretic but also cooling internally.
It stimulates gastric secretions and bile; it is anti-inflammatory.

Useful for indigestion, gastrointestinal spasms, flatulence, irritable bowel syndrome, nausea, respiratory congestion.
In general all the mints are antispasmodic, carminative, diaphoretic and decongestant.
Peppermint oil is also antiseptic and mildly anaesthetic.
Mints stimulate the digestion - drink a cup of peppermint or spearmint tea after meals and are warming and decongestant in colds and catarrh.
Peppermint, taken in tea, tincture or tablet form, can help to relieve nausea (including morning sickness), while the oil is used in stimulating rubs to soothe rheumatism and bronchial congestion.

Forms available: Teas, tinctures, essential oil, enteric-coated capsules of peppermint oil, chewing gum, mints.

Usage: Generally as an infusion (do not boil) for atony of stomach and intestine, for spasms of the digestive tract, for flatulence, jaundice, and biliary calculi.
Inhalations are very useful for head colds and throat infections. Also as an application to wounds.

CAUTION: Peppermint should not be given to babies or toddlers in any form: excess of the oil can irritate the stomach lining and misuse may lead to ulceration.
Exercise caution when giving peppermint tea to children because the menthol in the herb may make them choke.
The herb can also cause an allergic reaction in sensitive individuals.
Do not take this herb if you have insufficient hydrochloric acid in the stomach, gallbladder or bile-duct obstruction, inflammation or related conditions.
Do not apply the essential oil directly to mucous membranes; use the oil topically with care, diluted in vegetable oils as directed.
Do not add more than the directed amount to bath water.