Terpenes are the aromatic oils secreted in a cannabis plant’s trichomes that produce its unique smell and flavor profile. They are not exclusive to cannabis and are found throughout the plant kingdom—it’s the terpene limonene, for example, that gives lemons their signature citrusy smell. In cannabis, terpenes do more than just provide aroma; they are believed to work synergistically with cannabinoids like THC to produce nuanced effects, a concept known as the “entourage effect.”