Which plant's dried flower buds are used as the spice clove and contain the anesthetic compound eugenol? Clove is the answer.
Cloves are the unopened, dried flower buds of Syzygium aromaticum, an evergreen tree in the myrtle family. The tree is native to Indonesia's Maluku Islands, historically called the Spice Islands. Buds change from pale to green and then reddish before harvest; drying turns them into the familiar dark brown, nail-shaped spice.
Clove bud oil is especially rich in eugenol, which produces much of its warm aroma and sharp taste. Eugenol has local analgesic and anesthetic properties, explaining clove oil's long association with toothache relief. Dentistry has also used eugenol with zinc oxide in temporary restorative materials and root-canal sealers, although clove oil is not automatically safe or suitable for every medical use.
The main mix-up is confusing the spice with the whole plant. “Clove” can mean the dried bud, the tree, or its commercial oil, while the botanical plant is Syzygium aromaticum. Cardamom and nutmeg are also spices from different plants and do not produce the characteristic clove bud.