α-Calacorene is an aromatic sesquiterpene hydrocarbon that can be isolated from Reunion vetiver[1].
References
[1] Mizrahi I, et al. Essential oils and their constituents. Isolation of aromatic sesquiterpenes from Reunion vetiver oil. J Pharm Sci. 1969 Jun;58(6):738-40. DOI:10.1002/jps.2600580619