The clove of commerce is the air-dried unopened flower obtained from evergreen medium sized tree. The tree grows to a height of 10-12 mtrs and start flowering in about 7 years. It continues to produce flower for 80 or more years. It is a valuable spice of the orient. Clove clusters are plucked by hand when the are fully developed with a pronounced pink flush and then dried over several days in the sun. Unopened flower , leaves and stalks yield essential oil.