Melilotus

''Melilotus'', known as melilot, sweet clover, and kumoniga (from the Cumans),Bulgarian Folk Customs, Mercia MacDermott, pg 27 is a genus in the family Fabaceae (the same family that also includes the ''Trifolium'' clovers). Members are known as common grassland plants and as weeds of cultivated ground. Originally from Europe and Asia, it is now found worldwide.

This legume is commonly named for its sweet smell, which is due to the presence of coumarin in its tissues. Coumarin, though responsible for the sweet smell of hay and newly mowed grass, has a bitter taste, and, as such, possibly acts as a means for the plant to discourage consumption by animals. Fungi (including ''Penicillium, Aspergillus, Fusarium'', and ''Mucor'') can convert coumarin into dicoumarol, a toxic anticoagulant. Consequently, dicoumarol may be found in decaying sweet-clover, and was the cause of the so-called sweet-clover disease, recognized in cattle in the 1920s. A few varieties of sweet clover have been developed with low coumarin content and are safer for forage and silage.

The name ''sweet clover'' varies orthographically (''sweet-clover'', ''sweetclover'').

Uses

''Melilotus'' species are eaten by the larvae of some Lepidoptera species, such as those of the genus ''Coleophora'', including '' C. frischella'' and '' C. trifolii''.

''Melilotus'', often used as a green manure, can be turned into the soil to increase its nitrogen and organic matter content. It is especially valuable in heavy soils because of its deep rooting. However, it may fail if the soil is too acidic. It should be turned into the soil when 8 to 10 inches tall. Unscarified seed is best sown in spring when the ground is not too dry; scarified seed is better sown in late fall or even in the snow, so it will germinate before competing weeds the following spring.

'' Melilotus siculus'' (messina) is notable for its high combined tolerance to salinity and water logging. As of 2019, the "Neptune" variety has the highest tolerance and persistence under salinity among all pasture legumes, according to the Australian Department of Primary Industries and Regional Development. The salt-tolerant symbioant ''Ensifer medicae'' SRDI554 is recommended.

Others

Blue melilot (''Trigonella caerulea'') is not a member of the genus, despite the name.

Species

The genus ''Melilotus'' currently has nineteen recognized species:

* '' Melilotus albus'' Medik. (white sweet clover)
* '' Melilotus altissimus'' Thuill. (tall yellow sweet clover)
* '' Melilotus dentatus'' (Waldst. & Kit.) Pers.
* '' Melilotus elegans'' Salzm. ex Ser.
* '' Melilotus hirsutus'' Lipsky
* '' Melilotus indicus'' (L.) All. (annual yellow sweet clover, Indian sweet clover)
* ''Melilotus infestus