CHEMOSYSTEMATICS OF LEGUMINOSAE . FLAVONOID AND ISOFLAVONOID PATTERNS IN TRIBE GENISTEAE

Leaves of 128 species of 22 genera of the tribe of Genisteae sensu lato were surveyed for flavonoids and isoflavonoids. The isoflavones daidzein, formononetin, genistein and 5-O-methylgenistein were found variously in 73 species; they were detected in all except three of the genera of the Genisteae sensu strictu, but not in five associated genera. Leucoanthocyanidins were only found outside the Genisteae s.l. in Hypocalyptus and Loddigesia. Kaempferol, quercetin, luteolin or C-glycosylflavones based on luteolin or apigenin were noted in the majority of species; the distribution of the first three compounds in the genus Genista (46 species surveyed) largely followed sectional groupings. Luteolin was present in Genista mainly as the 7-glucoside but occurred exceptionally in three species of the section Spartioides as the 5-glucoside, galuteolin, earlier reported in the same family in Galega (Galegeae). The presence of galuteolin and 5-methylgenistein (in 17 spp.) in Genista and of glycoflavones in Cytisus (in 4 of 11 species) were the only clear-cut chemical differences between the morphologically similar genera Cytisus and Genista. The flavonoid data in general support Rothmaler's circumscription of the tribe and discount the more recent classification of Hutchinson. © 1970.