This popular herb began as native to Europe but has since been cultivated successfully in other temperate climates. It is particularly popular in North America for its promotion of healthy mood and emotional balance. A creeping perennial, it producing star-shaped yellow flowers containing long, abundant stamens and is traditionally harvested near the beginning of the summer months. The flowers bloom and can be harvested throughout the summer. Though useful to humans, it can be dangerous to livestock, sprouting up in pastures and causing photosensitivity to the grazing animals that feed upon it.