leaf oil of male baccharis punctulata dc. from argentina was analyzed at vegetative and at flowering stage. compound identification and differences are reported. the major component at vegetative stage (42-48%) was identified as the rare furanocadinane verboccidentafuran. 13c-nmr data of verboccidentafuran are assigned for the first time. other components are -elemene (9.1%), -elemene (3.1%), amorpha-4,7(11)-diene (7.5%), -bisabolene (2.4%), -cadinene (2.5%), cis-cadin-4-en-7-ol (5.0%), -muurolol (2.8%), -cadinol (2.0%) and -bisabolol (2.7%). at flowering stage, oils showed two major components: verboccidentafuran (22.4%) and the infrequent germacra-1(10),5-dien-4-ol (17.3%) which was unambiguously differentiated from the 4-ol diastereoisomer. other components are (e)--ocimene (2.4%), linalool (2.5%), -elemene (8.6%), -elemene (3.3%), amorpha-4,7(11)-diene (2.3%), elemol (2.6%), guaiol (2.4%), cis-cadin-4-en-7-ol (6.4%), -muurolol (3.4%) and -bisabolol (2.3%). female plant leaf oils showed similar tendency. all oils were sesquiterpene-rich. different composition is associated with flowering. major compounds are reported in b. punctulata for the first time.