Corn Mint

Common names

• Bo He
• Corn Mint

The corn mint is a perennial herb that grows up to two feet or 60 cm. This herb has a square stem, oval-shaped, dark, jagged and flat leaves, while whorls of pale lilac hued flowers grow from the axils of the leaves. The flowers of corn mint blossom all the way through the summer. This herb was referred to for the first time in Grandfather Lei's Discussion of Herb Preparation in 470 AD. It has been found that a Chinese prescription dating back to the 15th century had suggested the use of corn mint to treat bloody dysentery. Corn mint has a preference to grow in land that is being cultivated or in troubled places. In effect, all mints like as well as thrive in cool, damp spots where there is partial shade. Generally speaking, mints have an aptitude to endure a wide assortment of conditions and they are also able to grow in total sunlight. This herb has been named 'Corn Mint' since it was an ordinary 'weed' growing in fields where cereal crops are cultivated. Compared to other mints, the corn mint is less sweet, but encloses additional menthol. As a result, this species is widely used to prepare menthol flavoring extracts commercially. While the plant is still blossoming, it is steamed to facilitate the extraction of its oil. Prior to refining or processing, the menthol content in the plant varies between 60 per cent and 80 per cent. The corn mint plant is a fast growing variety and it spreads its reach along the length of exteriors by means of an arrangement of runners. Owing to their rapid growth, growing one plant of every preferred mint with a little care helps to provide in excess of sufficient mint for home use. Some of the mint species are more invasive compared to other varieties. It is important to take care while combining any mint with other plants or else the mint plant would invade the entire region. This is applicable even while growing mint species that are not so invasive. In order to regulate the growth of mints in an open surrounding, the plants ought to be planted in unfathomable, bottomless containers that are sunk into the ground. Alternately, they may also be planted in tubs and barrels above ground. The corn mint is an herb with a strong aroma and is cooling. According to the Chinese Medicine Herbal Theory, corn mint goes into the lung and liver conduits to cure the problems in these organs. It may be mentioned here that the ancient text written by Jia Suo Xue/ Jia Jiu Ru and titled 'Transforming the Significance of Medical Substances', which dates back to 1644 AD - during the reign of the Ming dynasty, affirms that the flavour of corn mint is caustic and hence, it is cool in nature. This helps in clearing heat, freeing as well as facilitating the assembling spots of the six yang channels on the head. The text also states that corn mint drives out pathogenic wind in every type of fever. As corn mint has a gentle cooling and penetrating nature, it is excellent at changing positions from the face to the head. Corn mint is effective in curing loss of voice, cooling the throat and problems of the mouth and teeth. The aroma of corn mint helps to open the orifices and, at the same time, is excellent in moving through the exterior muscle layer. In addition, corn mint diminishes fluid retention as well as scatters heat in the muscles.

Parts used

Aerial parts.

Habitat and cultivation

Indigenous to the temperate climatic regions of the northern hemisphere and extensively cultivated in China, corn mint is generally harvested twice or thrice each year. However, the best crop yield is during the early part of summer and in autumn. It is important to note that the fresh mint leaves ought to be used immediately or may be packed in plastic bags and stored in refrigerators for a few days. Alternately, one may also freeze the mint leaves in ice cube trays. On the other hand, dried mint leaves ought to be stored in hermetically sealed containers and placed in any cool, dry and dark place. The corn mint is a perennial plant and has several species and a wide variety, such as pineapple, orange, peppermint, apple mint and spearmint. All varieties of mints grow well in places receiving full sunlight or where there is partial shade. In addition, mints require a fertilized soil and regular watering. Unless the roots of the mint plants are confined by subterranean blockades, they spread at a very rapid pace and may invade the neighbouring areas. Depending on the region where the mint plant is cultivated, it can be harvested twice or thrice in a year. The mint leaves are collected in summer as well as in autumn when the branches of the herb are growing plentifully. Alternately, it may also be collected during the third phase of flowering. The herb is collected over several days when the weather is fine and dried out in the sun or even in the shade. Prior to using the dehydrated mint leaves, they ought to be soaked in water and cut into small pieces. A number of mint varieties may be propagated by their seeds. However, growing mint plants from seeds can prove to be an undependable procedure on two grounds - firstly, some varieties of mint are sterile and the seeds do not germinate; secondly, mint seed vary widely and often one may not end up with the variety he/ she had thought had planted. In effect, it is better to take cuttings of the mint plant from the runners of vigorous plants. The mint varieties that are most popular for cultivation include spearmint (botanical name Mentha spicata) and peppermint (botanical name Mentha x piperita). More recently, people have also taken a great liking for cultivating apple mint (botanical name Mentha suaveolens). Mints are considered to be excellent companion plants, denoting that they can grow well in the company of other plants too. In addition, mints are also helpful for plants growing in the neighbourhood as they are effective in repelling insects as well attracting helpful insects.

Constituents

Chemical analysis of the corn mint plant has shown that it encloses a volatile oil primarily including menthol. In effect, the menthol content of the volatile oil is up to 95 per cent. In addition, corn mint also encloses menthyl acetate, menthone, limonene, camphene and different terpenoids.