Two isorhamnetin glycosides and two sulphated derivatives are reported for the first time in the genus Senecio. The flavonoids of Senecio L. species were first studied when rutin (quercetin 3-rutinoside) was reported in S. erraticus Benth. subsp. barbareifolius Koch. [1], as well as the flowers of S. jacobaea L. [2]. The 3-glucosides and 3 rutinosides of both kaempferol and quercetin, and apigenin 7-glucoside as well as the rare 3-methylquercetin were later identified in 25 Senecio species [3]. Also present was the rare 6,8-di-C-rhamnosylapigenin and, in one species only (S. tamoides), the xanthone C-glucosides, mangiferin and isomangiferin [3].In the present study, three local species were studied. The flavonoids present were identified as the 3-glucosides of quercetin and isorhamnetin and isorhamnetin 3 rutinoside. Also present were the 3-monosulphate and 3,7(?)-disulphate of isorhamnetin (see Table 1). No C-glycosides of flavones or xanthones were detected.The presence of quercetin 3-glucoside is common in the Compositae [4,5]. On the other hand, the variation in the flavonoid chemistry within the Senecio species is not unexpected. Senecio is a cosmopolitan genus with about 1500 species, and chromosome numbers ranging fromx = 5 to 90 [6]. This represents the largest variation within the tribe Senecioneae.