Calendula is a genus of about only 20 species of plants in the Sunflower family, Asteracea. Calendula species are found in North East Africa, in regions in the Mediterranean Sea area and in Iran. Commonly named marigold, Calendula should not be confused with other plants also known as marigolds, such as corn marigold or desert marigold, which resemble Calendula but belong to different genera. The name of the genus Calendula comes from the Latin name calendae, meaning "first day of the month", presumably because one of its species, Calendula officinalis, blooms at the start of most months of the year.
Historically known for its medicinal and culinary value, the Calendula has been used by different cultures. Early Christians used to place it by the statues of the Virgin Mary and called it "Mary's Gold", whence its common name marigold. Also, in ancient India, Calendulas were the most sacred flowers where they used to be strung into garlands to adorn holy statues.
Calendula officinalis, commonly named pot marigold (Arabic common name: Nabaat al qaTifa), is the most cultivated species of the genus. It has been used traditionally as both a culinary and medicinal herb. Many of these uses persist today, like to make oils that protect the skin. The petals are edible and can be used fresh in salads or dried to color cheese or to replace saffron. Calendula officinalis has been reported to possess antiviral, anti-tumor and anti-inflammatory activities in-vitro.
It is a short-lived aromatic herbaceous perennial, growing to 80 cm tall with an erect stem and few branches. The leaves are spirally arranged, oblong, 5 to 17cm long, hairy on both sides, entire or sometimes weakly toothed. Flowers are big yellow-orange capitula of 4 to 7cm diameter surrounded by two rows of hairy bracts when cultivated, and yellow and much smaller with only one ring of petals in wild. Calendula officinalis grows on many different soil types and therefore is considered as one of the easiest flower to grow in a garden.
Professor Elie Barbour and co-workers, members of AUB Nature and Conservation Center, found an interesting potential application of Calendula officinalis in vaccination of poultry against 3 different viruses. It is not economically viable for the farmers to vaccinate their chickens with needles because it is stressful for the poultry and would take days and days to jab thousands of birds one by one. On the other hand, inoculation by spray or in drinking water enables mass vaccination but the virus has to be alive to work as a vaccine, which results in unwanted side effects such as respiratory inflammations and decreases in body weights. Professor Barbour and co-workers showed that Calendula officinalis alleviated the side injuries of the 3 live vaccine viruses.
Professor Elie Barbour stopped his work on Calendula officinalis after these findings but confided that its mysterious powerful bioactivities give a promising future for this plant and leave the door open to extensive research.
- PCR Use in Epidemiological Study of Avian Mycoplasmosis and Control of Gumboro by Herbal Extracts: View Abstract