Common Name: Melilot

General Information

Melilotus officinalis is a much-branched annual to biennial plant growing from a deep taproot. It has erect stems that become progressively woody as they age; it can grow 30 - 280cm tall[].
The plant is harvested from the wild for use as a food, medicine and source of materials. It is sometimes cultivated as a medicinal plant and is also grown as a green manure.

Known Hazards

The plant contains coumarin, a substance produced by the plant because it acts as an appetite suppressant and gives some protection from grazing - it is also the compound that gives some dried plants the smell of new mown hay. Coumarin is found naturally in many fruits, including strawberries, black currants, apricots, and cherries; it also has some medicinal applications, though it is also known to be toxic, affecting especially the liver and kidneys. Coumarin is of relatively low toxicity to humans – indeed it has often been used as a flavouring and aromatic additive in foods and other commodities. However, it can be much more toxic to other species, especially rodents and specifically rats.
The fresh plant material, consumed in moderation, is generally safe. However, the dried plant material, especially if it is not dried properly and is invaded by fungi, is potentially much more toxic as the coumarin breaks down to form other compounds that can have a strongly anticoagulant effect upon the blood. Warfarin, a well-known anticoagulant drug and rat poison, is one of those compounds produced from coumarin.

Botanical References

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Range

All around the Mediterranean region and Arabia, east through Asia to western China, the Himalayas

Habitat

Grassy fields and roadsides, avoiding acid soils[]. Steppe meadows, along rivers, among bushes, along roads, along railways, in fields and in ruderal places[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual/Biennial
Height	1.20 m
Pollinators	Bees
Cultivation Status	Cultivated, Wild

Cultivation Details

Melilotus officinalis is a plant of the temperate and Mediterranean zones of Europe and western Asia, where it is found at elevations up to 4,000 metres. It grows best in areas where annual daytime temperatures are within the range 12 - 24°c, but can tolerate 5 - 28°c[]. When dormant, the plant can survive temperatures down to about -5°c, but young growth is more tender and can be severely damaged at 0°c[]. It prefers a mean annual rainfall in the range 450 - 800mm, but tolerates 300 - 1,600mm[].
Grows best in a sunny position, toleraing light shade[]. Prefers a well-drained to dry, neutral to alkaline soil in a sunny position[]. One of the best legumes to grow in highly alkaline soils[]. Prefers a clay or a saline soil[]. Succeeds in soils of low fertility[]. Prefers a pH in the range 6 - 7, tolerating 5 - 8.5[]. Established plants are drought tolerant[].
The flowers are rich in nectar and pollen making this a good bee plant[, , , ].
If they are cut back before flowering, the plants will grow on for at least another year before dying[].
The dried plant has a sweet aromatic fragrance like newly mown hay[].
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

Root[, , ]. Consumed as a food by the Kalmuks[].

Young shoots - cooked. Used like asparagus[]. Young leaves are eaten in salads[]. The leaves and seedpods are cooked as a vegetable[, , ]. They are used as a flavouring[]. Only fresh leaves should be used, see the notes above on toxicity[].

The crushed dried leaves can be used as a vanilla flavouring in puddings, pastries etc[, , ]. Caution is advised, see the notes above on toxicity.

Flowers - raw or cooked[]. The flowers and seeds are used as a flavouring[]. The flowers also give an aromatic quality to some tisanes[].

Medicinal

Melilot, used either externally or internally, can help treat varicose veins and haemorrhoids though it requires a long-term treatment for the effect to be realised[]. Use of the plant also helps to reduce the risk of phlebitis and thrombosis[].
Melilot contains coumarins and, as the plant dries or spoils, these may become converted to dicoumarol, a powerful anticoagulant[]. Thus the plant should be used with some caution, it should not be prescribed to patients with a history of poor blood clotting or who are taking warfarin medication[]. See also the notes above on toxicity[].

The flowering plant is antispasmodic, aromatic, carminative, diuretic, emollient, mildly expectorant, mildly sedative and vulnerary[, , , , , , ]. An infusion is used in the treatment of sleeplessness, nervous tension, neuralgia, palpitations, varicose veins, painful congestive menstruation, in the prevention of thrombosis, flatulence and intestinal disorders[, ].
Externally, it is used to treat eye inflammations, rheumatic pains, swollen joints, severe bruising, boils and erysipelas, whilst a decoction is added to the bath-water[, ].
The flowering plant is harvested in the summer and can be dried for later use[].

A distilled water obtained from the flowering tops is an effective treatment for conjunctivitis[].

Agroforestry Uses:

The plant can be used as a green manure, enriching the soil with nitrogen as well a providing organic matter[].
Melilotus officinalis is one of the best legumes for soil improvement. The widely branched, deeply penetrating taproots open up the subsoil enabling the roots to use nutrients not available to plants with shallow roots. When the plants decay, the nutrients in the roots are released for use by other crops[].
The plant is an excellent source of nectar and pollen for honey bees[].

Other Uses

The leaves contain coumarin and they release the pleasant smell of newly mown hay when they are drying[]. The leaves are dried and used as an insect repellent[, ], especially in order to repel moths from clothing[, , ]. They can be put in pillows, mattresses etc[].

Poorly dried or fermented leaves produce a substance called dicoumarol. This is a potent anti-coagulant which is extremely poisonous in excess, it prevents the blood from coagulating and so it is possible to bleed to death from very small wounds. Dicoumarol is used in rat poisons[].

An extract of the aerial portions of the plant is used as an ingredient in commercial cosmetic preparations as an astringent, masking agent and soothing agent[].
An extract of the flowers is used as an ingredient in commercial cosmetic preparations as anastringent, emollient and skin conditioner [].
An essential oil distilled from the plant is used as an ingredient in commercial cosmetic preparations as a perfuming agent[].

Propagation

Seed - sow spring to mid-summer in situ[]. Pre-soaking the seed for 12 hours in warm water will speed up the germination process, particularly in dry weather[]. Germination will usually take place within 2 weeks.
The seed produced can have either hard or soft seedcoats. Soft-coatd seeds germinate quickly without treatment, but hard-coated seeds can remain dormant in the soil for several years before germinating. In cultivation, the hard-coated seed requires pre-soaking in warm water in order to soften the seedcoat[].