Cloves are unopened flower buds from the clove tree, harvested and dried when ripe red. They are rich in strong flavor oils stored primarily in the round head of the clove but also found throughout the stalk which is also contains oil glands. Their predominant flavor compound is eugenol, which makes whole cloves intensely aromatic, and also warm and pungent in taste.
Though this aromatic oil can also be found in allspice, nutmeg, and cinnamon, there's such an abundance in cloves that eugenol is also called 'clove oil.' Cloves can be found in a wide variety of cuisine from Asia to Africa and from the Middle East to India. It can add aroma to hot winter-weather beverages; a warm astringency to meats and marinades; and a lightly sweet pungent spice to fruits. Clove spice is however, intense and so its strength requires sparing use.