Sweet clover (Melilotus officinalis
) is an annual or biennial, erect or decumbent herb with trifoliate leaves. During its first year of growth, it produces a single stem with several branches. In the second year, it increases the number of stems, grows and begins producing flowers and seeds. M. officinalis
has course stems with 3-pinnate leaves and axillary flowers. Leaflets are small, pea-like clusters of yellow to white flowers which bloom April to October in North America. M. officinalis
is indigenous to central Europe and north-west Asia. However, it has been introduced to temperate regions worldwide.
All parts of M. officinalis
contain coumarin, which is able to convert to dicoumarin, the active principle in Warfarin, a powerful anticoagulant toxin, when the plant spoils or gets damaged. Poisoning causes similar symptoms as whats seen in cases of anticoagulant rodenticide poisoning.