Herb's Introduction
Melilotus indicus (L.) All., commonly known as Indian Sweet Clover or Vanamethika, is a versatile annual herb belonging to the Fabaceae (pea or legume) family. It is an erect plant that can grow from 15 to 60 cm tall, although it may reach up to 100 cm under favorable conditions. While native to a wide region spanning southern Europe, northern Africa, and parts of Asia, it has naturalized and become a common sight across the globe, often found as a weed in fields, waste places, and along roadsides.
The plant is distinguished by its trifoliate leaves and small, dense racemes of yellow flowers. It is well-known for the sweet, hay-like scent it emits, which is particularly strong when the plant is crushed or dried. This characteristic aroma is due to the presence of a compound called coumarin. Historically, Melilotus indicus has been used for various purposes, including as a food source, a medicinal herb, a green manure to improve soil quality, and a natural insect repellent.
Name in Different Countries
English: Indian Sweet Clover, Yellow sweet clover, Small Melilot, Sour Clover, Small-flowered Sweet Clover, Annual Yellow Sweetclover, Hexham Scent.
Arabic: قُرط (Qurt), نَفَل (Nafal).
Assamese: বন মেথী (Ban Methi).
Bengali: বন মেথী (Ban methi).
Chinese: 野苜蓿 (Yě mùxù).
Dutch: Kleine honingklaver.
Finnish: Intianmesikkä.
French: Mélilot à petites fleurs.
German: Kleinblütiger Steinklee.
Hindi: बन मेथी (Ban methi), Morila, Senji methi.
Marathi: रान मेथी (Ran methi).
Nepali: मेथी घाँस (Methi ghans).
Portuguese: Anafe-menor.
Russian: Донник индийский (Donnik indiyskiy).
Sanskrit: वनमेथिका (Vanamethika).
Swedish: Dvärgsötväppling.
Terminology
The plant's botanical name, Melilotus indicus, is a combination of Greek and Latin roots. The genus name Melilotus comes from the Greek words "meli" (honey) and "lotos" (legume or clover), referring to the plant's value as a source of nectar for bees. The species epithet "indicus" denotes its origin, pointing to India as a part of its native range.
Its synonyms, such as Trifolium indicum, reflect its historical classification and close relationship to the clover genus (Trifolium). Other common names like "Sweet Clover" and "Sour Clover" allude to its characteristic scent and taste, while names like "Vanamethika" in Sanskrit and "Ban Methi" in Hindi translate to "forest fenugreek," highlighting a traditional association with the culinary herb fenugreek (Trigonella foenum-graecum) due to a similar appearance and aromatic qualities.
Availability
Melilotus indicus is widely available and can be found growing in a variety of habitats across temperate and tropical regions worldwide. It is a common weed of agricultural lands, roadsides, and disturbed areas. While it is not widely cultivated for commercial purposes, its seeds and dried parts can sometimes be found in traditional herbal medicine markets. It is also grown as a fodder crop and a green manure due to its ability to fix atmospheric nitrogen in the soil through a symbiotic relationship with certain bacteria.
External Look
Plant: An erect annual herb, typically growing 15-60 cm tall, with a branching, pubescent (hairy) stem.
Leaves: The leaves are compound, trifoliate (composed of three leaflets), and arranged alternately on the stem. Each leaflet is oblong or lanceolate, measuring 1.2-2.5 cm long and 7-10 mm broad. The margins of the leaflets are finely toothed.
Flowers: Small, bright yellow flowers, 2-3 mm long, are borne in dense, elongated clusters called racemes. Each raceme can contain 10-16 flowers. The flowers are papilionaceous, meaning they have a structure resembling a butterfly, characteristic of the pea family.
Fruit: The fruit is a small, one-seeded pod (legume) that is typically 1.5-4 mm long. It is prominently veined and can appear globose (round) or subglobose, with a wrinkled texture.
Scent: The fresh plant has a slightly bitter, sweet, hay-like scent when crushed. This aroma becomes much more pronounced when the plant is dried, which is a key identifying feature.
Healing Properties
Melilotus indicus has been used in traditional medicine for its various healing properties, which are largely attributed to the presence of compounds like coumarin, flavonoids (e.g., quercetin), and phenolic acids. Scientific studies have explored some of these traditional uses.
Anti-inflammatory and Analgesic: The plant is traditionally used to treat swellings and pain. Research suggests its extract has significant analgesic (pain-relieving) and anti-inflammatory effects.
Anticoagulant: The coumarin present in the plant can be converted into dicoumarol, a powerful anticoagulant (blood thinner), particularly when the plant is dried improperly and becomes moldy. This property, while beneficial for some medical conditions like venous disorders, also poses a significant risk of toxicity.
Anticancer: Preliminary studies have indicated that extracts of Melilotus indicus have cytotoxic effects on various cancer cell lines, including those of the liver, colon, and breast. It is also being investigated for its potential to inhibit skin cancer development.
Antioxidant: The plant contains antioxidants like quercetin, which help to neutralize free radicals in the body and protect against oxidative stress.
Antispasmodic: Traditionally, it is used to relieve spasms, particularly those of the gastrointestinal tract.
Emollient and Astringent: The plant is used topically to soothe and soften the skin, and its astringent properties are used for treating cuts, wounds, and skin eruptions.
Laxative and Diuretic: The whole plant is traditionally used as a strong laxative and purgative. An infusion of the leaves and seeds is also used to treat stomachaches and infantile diarrhea.
Advantages
The advantages of Melilotus indicus lie in its versatility and chemical composition.
Soil Improvement: As a legume, it fixes atmospheric nitrogen, enriching the soil. This makes it an excellent green manure, particularly for depleted or saline soils.
Ecological Resilience: It is a hardy plant that can thrive in challenging environments, including semi-desert and moderately saline areas, where other conventional crops may fail.
Potential for Modern Medicine: Its phytochemicals, particularly coumarin and quercetin, show promising results in scientific research for their anti-inflammatory, antioxidant, and anticancer properties, opening doors for the development of new drugs.
Natural Insect Repellent: The coumarin content makes the plant a natural repellent for insects, such as bedbugs.
Disadvantages and Cautions
Despite its benefits, the plant has significant disadvantages, primarily related to its toxicity.
Toxicity to Livestock: The plant is toxic to livestock, especially when dried and improperly cured. The conversion of coumarin to dicoumarol by mold can cause a condition known as "sweet clover bleeding disease," leading to fatal internal bleeding in animals.
Human Health Risks: While fresh plant material is generally considered safe for human consumption in moderation, the dried and fermented plant can be highly dangerous. Its anticoagulant properties can interact with blood-thinning medications, and large doses can be toxic to the liver and kidneys.
Weed Potential: Due to its aggressive growth and ability to spread rapidly, it is considered an invasive weed in many parts of the world, capable of outcompeting native flora and reducing crop yields.
Uses
Folk Medicine:
External: The juice of the plant is applied directly to cuts and wounds. The whole plant is used as a plaster for swellings. Leaf extracts mixed with lemon juice are applied to skin eruptions and to relieve itching.
Internal: The seeds are used to treat bowel complaints and infantile diarrhea. The plant is taken as a strong purgative.
Fodder: In some regions, it is used as a forage crop for cattle, but only under careful management to avoid the risk of toxicity.
Green Manure: It is widely used as a cover crop to improve soil fertility by fixing nitrogen.
Insect Repellent: The plant is used in beds and closets to repel bedbugs and moths.
Using Way
Traditional methods of using Melilotus indicus vary depending on the ailment and form of the plant.
For External Application:
Plaster/Poultice: The whole plant or leaves are crushed into a paste and applied directly to the affected area, such as swellings or bruises.
Juice/Extract: The fresh plant is squeezed to extract its juice, which is then applied to wounds or skin irritations.
For Internal Consumption:
Infusion: An infusion of the leaves and seeds is prepared for treating stomach-related issues.
Gruel: The seeds are sometimes ground and made into a gruel for treating bowel complaints.
As a Vegetable: In some regions, such as Pakistan, the fresh young plant is cooked and eaten as a vegetable.
Important Note: Given the significant toxicity risks associated with the plant, especially when dried or fermented, internal use should be approached with extreme caution and under the guidance of a qualified healthcare professional.
Conclusion
Melilotus indicus, or Vanamethika, is a remarkable plant with a dual identity. On one hand, it is a persistent weed and a toxic threat to livestock, while on the other, it is a valuable nitrogen-fixing green manure and a source of compounds with significant medicinal potential. Its traditional uses in Ayurveda and other folk medicine systems, particularly for treating skin ailments, swellings, and gastrointestinal issues, are well-documented. However, the presence of coumarin, which can be converted into a potent and dangerous anticoagulant, necessitates extreme caution, particularly regarding its internal use. While modern research is shedding light on its anti-inflammatory, antioxidant, and anticancer properties, further studies are required to establish safe and effective therapeutic dosages and applications. As with all powerful medicinal plants, a deep understanding of its properties, and its risks, is crucial for its safe and beneficial use.
