The officinal concern, in scientific Latin Calendula officinalis, is an herbaceous plant, with yellow flowers or orange yellow, whose flowering starts at the first days of spring and can last throughout almost the whole year. The flowers have the characteristic to be closed at night and to be reopened as soon as the sun is sufficiently high in the sky. Very common in the Mediterranean areas, Calendula grows there in the majority of gardens and waste lands without needing to be planted, having the wind acting as a gardener. Its Latin name appears related to the calends (first day of the month among Romans), to perhaps underline the fact that it flowers all year. Its sheets are alternate, oblong and sessile.

Its petals make it possible to falsify the saffron.

The dried flowers are used. Out of infusion, the plant is an anti-inflammatory drug, hypotensor, spasmolytic, immunostimulant and hypocholesterolemiant. In external use it is an excellent anti-inflammatory and anti-venomous. It is anti-bacterial, antiviral and anti-fungic. In medicine, Calendula is known for its healing virtues.