Melilotus officinalis - seeds

Yellow Sweet Clover, known by its Latin name Melilotus officinalis, is an annual or biennial herbaceous plant. Characterised by a yellow summer flowering, trifoliate leaves, and a taproot, it is used as a nitrogen-fixing forage plant and green manure, a nectar-rich plant loved by bees, providing beekeepers with excellent honey yields. It is also an edible plant. It grows in all types of soil, even very dry ones. The only conditions that are not suitable for it are shade and acidic soils.

Yellow Sweet Clover or Melilotus officinal belongs to the Fabaceae family (formerly legumes). It is widespread in the plains of temperate regions in Europe. It grows in limestone clearings, lightly wooded cliffs, meadows and weed-infested fields, as well as in open and disturbed sites, riparian zones, meadows, pastures, roadsides, ditches, vacant lots, and fallow land. It is a nectar-rich herbaceous plant, reaching a height of 30 cm to 1.20 m, depending on the growing conditions, with leaves composed of 3 leaflets. The light green stems are round or slightly furrowed and often branched. The alternate leaves are trifoliate and scattered along the stem. The upper stems end in narrow racemes of yellow flowers that tend to hang down from the central peduncle of the raceme. Each flower is about 8.5 mm long and consists of 5 yellow petals and a light green calyx with 5 teeth. The flowers are small, soft, tubular at the base, and widen towards the outer edges. Its flower clusters appear from June to September. The plants usually flower and die in the second year of growth. The Yellow Sweet Clover is cold-resistant down to -15°C. It has deep roots, which help to loosen the soil.

Melilotus officinalis is adapted to a wide range of climatic conditions and grows in practically all types of soils, including very poor soils. It prefers soils with a neutral pH or a tendency towards limestone. It only needs adequate moisture during germination. It is then capable of growing in extremely dry conditions. It can be invasive, so it is important to remove the flowers before they seed. This plant nourishes and improves the soil by providing it with various nutrients and stimulating soil microbial life. Its roots loosen and aerate the soil. Used as green manure, it also protects soils from leaching (nutrient loss in sandy soil), rain compaction (formation of a crust in loamy soil), and erosion (caused by runoff in case of heavy rain on sloping terrain). This vegetative cover also helps to limit weed growth by preventing the growth of unwanted plants. Green manures are sown on uncultivated plots or between rows of vegetables. They are either naturally destroyed by frost or cut before seed formation. Once destroyed, they can be left in place as mulch, or crushed and incorporated into the top layers of the soil, or collected and added to compost.

Yellow Sweet Clover is an edible plant rich in vitamin C, with leaves that emit a sweet smell reminiscent of hay, derived from coumarin. Its young leaves can be eaten raw in small quantities in salads, and its seeds can be used as a spice. Although Yellow Sweet Clover has medicinal properties, it is strongly advised not to harvest it for self-use as a "treatment" and not to dry it oneself. Improperly dried coumarin transforms into dicoumarol, a highly toxic compound. It is an antispasmodic, antiseptic, and diuretic. It is also used to aid sleep and calm nervousness. Consumed in very high doses, sweet clover can be toxic.