It is closely related to Datura, belonging to the same nightshade family, solanaceae. Brugmansia blooms dangle like great trumpets or bells while Datura blooms stand erect.
Calendula officinalis (pot marigold, ruddles, common marigold, garden marigold, English marigold, or Scottish marigold) is a plant in the genus Calendula of the family Asteraceae.