Volatile chemical composition does not support a native status of the cryptogenic Bupleurum fruticosum (Apiaceae) in peninsular Italy

Cryptogenic (or doubtfully native) species could have relevant implications in biogeography and in nature conservation. Bupleurum fruticosum is native in Sicily, Sardinia, and Liguria, whereas the single Tuscan population is considered cryptogenic. Given its pharmacological activity, several studies investigated the essential oil composition of this species, but an analysis of geographic pattern of the chemical composition was never performed. In the present study, the essential oil composition of the Tuscan population was investigated for the first time, and a comparison with other populations from literature was performed in order to provide useful data to disentangle its cryptogenic status. Our results highlight a major similarity of plants from Tuscany with geographically distant populations from Portugal and France, whereas other Italian populations show a very different chemical composition. These results do not support a native status of Tuscan population, suggesting an ancient human introduction. Our analysis also revealed a high percentage of (Z)-β-ocimene in stems of plants from Tuscany.