Cannabis is the king of terpenes

“Cannabis is a unique plant,” said Verzua. “It is one of the oldest surviving plants on Earth. They have found at least one hundred forty different types of terpene available in the plant at any one time. Whereas, you take most other plants or herbs—something like lavender or eucalyptus—they produce a high abundance of a single type of terpene, as opposed to the one hundred forty or so [of cannabis].”

Terpenes act as modulators for cannabinoids within the brain, meaning that terpenes will either turn on or turn off cannabinoid receptors in the brain. Few clinical publications on cannabis terpene exist, and further science is necessary in fully understanding the modulation effects of terpenes. 

Myrcene, for instance, increases cell permeability and allows cannabinoids to be absorbed faster than they would get on their own.