In this paper, the isolation of the alkaloid nemorensine from Senecio nemorensis L., var. subdecurrens GRISEB., S. nemorensis L. , ssp. Jacquinianus (RCHB.) DURAND and S. nemorensis L., ssp. fuchsii, var. nova (ZLATNIK) has been described. On the basis of some chemical reactions and the interpretation of the PMR and mass spectra, the structure V has been assigned to nemorensine.