Frankincense or olibanum (Arabic language: لبٌان, lubbān) is an aromatic resin obtained from trees of the genus Boswellia, particularly Boswellia sacra (syn. B. carteri, B. thurifera) (Burseraceae). It is used in incense as well as in perfumes.
Frankincense is tapped from the very scraggly but hardy Boswellia tree through scraping the bark and allowing the exuded resins to bleed out and harden. These hardened resins are called tears. There are numerous species and varieties of frankincense trees, each producing a slightly different type of resin. Differences in soil and climate create even more diversity in the resin, even within the same species.
These trees are also considered unusual for their ability to grow in environments so unforgiving that the trees sometimes seem to grow directly out of solid rock. The deep roots prevent the tree from being torn away from the stone during the violent storms that frequent this region; the tears from these hardy survivors are considered superior due to their more fragrant aroma. The aroma from these tears are more valuable for their presumed healing abilities and are also said to have superior qualities for religious ritual.
Tapping is done 2 to 3 times a year with the final taps producing the best tears due to their higher aromatic terpene, sesquiterpene and diterpene content. High quality resin can be visually discerned through its level of opacity. Omani frankincense is said to be the best in the world, although quality resin is also produced in Yemen, and along the north coast of Somalia.
Recent studies have indicated that frankincense tree populations are declining due to over-exploitation. Heavily tapped trees have been found to produce seeds that germinate at only 16% while seeds of trees that had not been tapped germinate at more than 80%.