This species of Mint, a native of most parts of Europe and parts of Asia, is the Pulegium of the Romans, so named by Pliny from its reputed power of driving away fleas - Pulex being the Latin for flea, hence the Italian pulse and the French puce. This name given the plant in ancient times has been retained as its modern specific name. It is sometimes known to the country people as 'Run by the Ground' and 'Lurk in the Ditch,' from its manner of growth.It was formerly much used in medicine, the name Pennyroyal being a corruption of the old herbalists' name 'Pulioll-royal' (Pulegium region), which we meet also in the Middle Ages as 'Piliole-rial.' It has been known to botanists since the time of Linnaeus as Mentha Pulegium.One of its popular names is 'Pudding Grass,' from being formerly used in stuffings for hog's puddings ('grass' being, like 'wort,' a word simply meaning 'herb'). It is still used abroad in various culinary preparations, but in this country, it is now in disuse, as its taste and odour are too pronounced.A famous stuffing was once made of Pennyroyal, pepper, and honey.
description---Pennyroyal is the smallest of the Mints and very different in habit from any of the others. Two forms of the plant are met within Great Britain: the commonest, the variety decumbent, has weak, prostrate stems, bluntly quadrangular, 3 inches to a foot long, which readily take root at the lower joints or nodes. The leaves are opposite, shortly stalked, more or less hairy on both sides, roundish oval, grayish green, about 1 to 1 1/2 inch long and 1/2 inch broad. The flowers are in whorled clusters of ten or a dozen, rising in tiers one above the other at the nodes, where the leaves spring in pairs, beginning about the middle of the stem, their color reddish purple to lilac blue, and in bloom during July and August. The seed is light brown, oval and very small. The other variety, erect, has much stouter stems, not rooting at the nodes and not decumbent, but erect or suberect, 8 to 12 inches high. It is rarer, but the best for cultivation, as it can be raped and tied up in bundles easily, whereas the stems of documents form a dense green turf, the flowering stems, sparingly produced, Lying on the leafy cushions of the plant. There are other varieties on the Continent. The plant has been introduced into North and South America. It is mentioned in the Herbals of the New World as one of the plants the Pilgrim Fathers introduced.It is found wild and naturalized throughout the civilized world in strong, moist soil on the borders of ponds and streams, and near pools on heaths and commons. Gerard speaks of it as found abundantly: sundried a common at Mile End, near London, about the holes and ponds their sundry places, from whence poore women bring plenty to sell in London markets.'Turner says:'It crepeth much upon the ground and hath many little round leves not unlyke the leves of mesierum gentil, but that they are a little longer and sharper and also little indented rounde about, and grener than the leves of mariurum ar. The leves grow in little branches even from the roote of certayn ioyntes by equall spaces one devyded from an other. Whereas the leves grow in little tuftes upon the over partes of the braunches.... Pennyroyal groweth much, without any setting, besyd hundsley (Hounslow) upon the heth beside a watery place.'Like most of its near relatives, Pennyroyal is highly aromatic, perhaps even more so than any other Mint, containing an essential oil resembling in properties that of other mints, though less powerful. The flavour is more pungent and acrid and less agreeable than that of Spearmint or Peppermint.Pennyroyal was in high repute among the Ancients. Both Pliny and Dioscorides described its numerous virtues. In Northern Europe it was also much esteemed, as may be inferred from the frequent references to it in the Anglo-Saxon and Welsh works on medicine.'The boke of Secretes of Albertus Magnus of the vertues of Herbes, Stones and certaine Beastes' states that, by putting drowning flies and bees in warm ashes of Pennyroyal 'they shall recover their Iyfe after a little tyme as by ye space of one houre' and be revived.Pennyroyal is often found in cottage gardens, as an infusion of the leaves, known as Pennyroyal Tea, is an old-fashioned remedy for colds and menstrual derangements.Cultivation---Locally, Pennyroyal grows abundantly, but being required by the hundredweight it has been cultivated to a certain extent in this country, on account of the difficulty of obtaining sufficient quantities from the widely separated localities in which it is found.As a crop, it presents uncertainty, being diminished by drought, its natural habitat being on moist heaths and commons by the sides of pools. It is easily grown from seed and succeeds best in loamy soil, in a moist situation, but propagation is commonly by division of old roots in autumn or spring, March or April, like Spearmint, or more rarely by cuttings. The roots may be divided up in September where the winters are mild, in April where the winters are frosty.In planting, allow a space of 12 inches between the rows and 6 inches between the plants in the row. Water shortly afterwards should the weather be at all dry. When a good stock of healthy roots has been obtained, Pennyroyal may be forced with advantage. The creeping underground roots grow in horizontal masses, as with the other mints and if some of these are taken up at any time during the winter and laid out on a bed of good soil, covering them with 2 or 3 inches of the same, they will soon push up fresh shoots in quantity. They can be put in boxes in a moderately warm house or pit. If all the tops are not wanted they may be made into cuttings, each with four or five joints, and, inserted in boxes of light, sandy soil, will soon form roots at the same temperature, and after being duly hardened off, may be planted out in the open, in due course, and a healthy, vigorous stock thus be maintained. Towards the close of autumn all the stalks that remain should be cut down to the ground and the bed covered with fresh soil to the depth of 1 inch.Plantations generally last for four or five years when well managed and on favourable soil, but frosts may cause the crop to die off in patches, so it is a safe plan to make new plantings yearly.
Harvesting---Pennyroyal is mostly sold in the dry state for making tea, the stems being cut when the plant is just about to flower and dried in the usual manner.---Constituents---The fresh herb yields about 1 per cent of a volatile oil, oil of Pulegium, a yellow or greenish-yellow liquid, obtained by distillation, and having a strong aromatic odour and taste. The chief constituent is ketone pulegone.A yield of 12 lb. of oil to the acre of crop is considered good.Medicinal Action and Uses---Pliny gives a long list of disorders for which Pennyroyal was a supposed remedy, and especially recommends it for hanging in sleeping rooms, it being considered by physicians as more conducive to health even than roses.It was likewise thought to communicate its purifying qualities to water, and Gerard tells us: 'If you have Pennyroyale in great quantity dry and cast it into corrupt water, it helpeth it much, neither will it hurt them that drink thereof.' As a purifier of the blood, it was highly spoken of: 'Penny-royale taken with honey cleanseth the lungs and cleareth the breast from all gross and thick humours.'It was deemed by our ancestors valuable in headaches and giddiness. We are told: 'A garland of Penny-royale made and worn about the head is of great force against the swimming in the head and the pains and giddiness thereof.'Pennyroyal Water was distilled from the leaves and given as an antidote to spasmodic, nervous and hysterical affections. It was also used against cold and 'affections of the joints.'Culpepper says of Pennyroyal:'Drank with wine, it is good for venomous bites, and applied to the nostrils with vinegar revives those who faint and swoon. Dried and burnt, it strengthens the gums, helps the gout, if applied of itself to the place until it is red, and applied in a plaster, it takes away spots or marks on the face; applied with salt, it profits those that are splenetic, or liver grown.... The green herb bruised and putinto vinegar, cleanses foul ulcers and takes away the marks of bruises and blows about the eyes, and burns in the face, and the leprosy, if drank and applied outwardly.... One spoonful of the juice sweetened with sugar-candy is a cure for hooping-cough.'Its action is carminative, diaphoretic, stimulant and emmenagogic, and is principally employed for the last-named property in disorders caused by sudden chill or cold.It is also beneficial in cases of spasms, hysteria, flatulence and sickness, being very warming and grateful to the stomach.The infusion of 1 OZ. of herb to a pint of boiling water is taken warm in teacupful doses, frequently repeated, and the oil is also given on sugar, as well as being made up into pills and other preparations.In France and Germany oil of Pennyroyal is also used commercially.