In addition to a hydrocarbon fraction identical with those of other Petasites species, the light petroleum extract of Petasites paradoxus contained: kablicin, angelyljaponicin, kablikopetasin, furoeremophilane and a hitherto unidentified triterpenic alcohol C30H50O. These substances are identical with those encountered in Petasites kablikianus. The assumed parallel phylogenetic origin of both species, and their hybrid origin from the same parent taxa, seems to be confirmed. © 1970.