Calendular, Marigold

Calendula, well known as one of the ornamental marigolds, blooms month after month from early spring to first frost. Because "calend" means month in Latin, the plant's lengthy flowering season is believed to have given calendula its name. The herb has been used to heal wounds and treat inflamed skin since ancient times. An active ingredient that might be responsible for calendula's traditional medicinal properties has not been discovered.

One theory suggests that volatile oils in the plant act synergistically with other constituents