Herbs: Sweet Clovers; Medicinal Properties, Nutrition and Toxicity
The majority of clovers are from the Trifolium or “three leaves” species which were originally imported to North America from Eurasia as a hay crop, for pasture (honeybees) and to enrich farm soil. Another similar species regarded as clover, but not as true clover, are the melilotus species, also known as sweet clovers (melilot). The two most abundant species are yellow sweet clover (melilotus officinalis) and white sweet clover (melilotus alba). Melilotus meaning “honey lotus.” Both sweet clover types look very similar except one has yellow flowers and the other white flowers.
Aside from their many agricultural benefit’s, the fragrant flowers of sweet clovers were used as an herb to flavor Gruyere cheese, snuff and also pipe tobacco. This plant species was traditionally valued by Kalmuks, and also present day Chinese, as food and a good source of protein and minerals. The seeds of yellow and white sweet clover have a similar chemical composition to Tonka beans (both species are from the pea or Fabaceae family), for which they have been used to substitute.
Unlike many Trifolium species which are annuals, white and yellow sweet clover are biennials. They grow up to 6 feet tall, and their three leaf leaflets have slightly serrated edges, a trait typical of clovers. The time for foragers to pick clover flowers is from June to July, although Clover leaves are at their best in early spring. Sweet clovers grow abundantly in over grown fields, disturbed habitats, prairies and along coastal areas in many temperate regions.
Medicinal Properties: Clovers have a long, almost forgotten, tradition in folk medicine. Before vasodilators were invented people smoked cigarettes made with dried clover leaves to relieve asthma. Tea made from the flowers, leaves and seeds was used as a remedy for the common cold, bronchitis and heartburn. The taste of clover tea is slightly bland and benefits from the addition of other herbs, such as mint. Medicinally, this herb is thought to have anti-inflammatory, antispasmodic and soothing properties. An infused oil made from sweet clovers is thought good for detoxification of the liver and gallbladder. Traditionally it was used for convalescence, to provide nourishment and strengthening.
Are Sweet Clover Flowers and Leaves Toxic ?: Some years ago the reputation of sweet clover as good cattle feed took a serious blow when dairy cows in Wisconsin, which had fed on the plants, began mysteriously getting sick and dying. After an investigation it turned out that rotten or decomposing clover leaves turned coumarin, a substance found in sweet clover that is harmless to animals and humans, into dicoumarin. Dicoumarin is a natural blood thinner, which, taken in large amounts, causes internal bleeding. This discovery led to the development of the first anticoagulant drug, warfarin; now a life sustaining medication for millions (also dicoumarol). As for the cows, those who were at risk were given large doses of vitamin K which saved their lives.
Although coumarin is thought harmless to humans in small quantities, and may in fact be beneficial, it’s recommended that people consume no more than 4000mg. Doing so is know to have caused headaches, vomiting and nausea. Also, for the aforementioned reason it is best to only eat the youngest freshest leaves. Clover flowers have a high nectar content and are used to make wine, although fermentation has been known to cause an unpleasant toxic reaction, so other wildflowers might be a better choice.
Coumarin or cumarin is also found in vanilla and cinnamon. Some say that the scent of sweet clovers is similar to those spices, although vanilla is a member of the orchid family and cinnamon the laurel family. This fragrant similarity led to the use of sweet clovers as an herb flavoring and substitute for vanilla, and also Tonka beans. Sweet clover flowers are dried and added to closets and dresser draws to impart their sweet scent; they also act as moth repellent.
Sweet clover is used in the preparation of salve; skin creams or ointments. Its thought that coumarin may help heal skin lesions, burns and relieve skin irritations by stimulating lymph flow. It also has anti-inflammatory,moisturizing effects and is suitable for sensitive skin.
Nutritional Value: Because clovers are legumes and in the same botanical family as peanuts, soy, beans and lentils, they are a source of protein but alone they lack in certain essential amino acids. Therefore clovers should complement whole grains, such as brown rice or wheat, to create a better quality protein.
Aside from protein, clovers are extremely nutritious providing vitamin A or beta carotene, also vitamin’s C, B1,B2,B3,B5,B6,B9 and B12. This herb also contains antioxidant rich bioflavonoids or flavonoids, including quercetin and kaempferol. Clovers are a source of the minerals, manganese, magnesium, copper, zinc and selenium.
Primary image, flickr.com.
Yellow sweet clover; flickr.com.