Flavonoid glycosides of Astragalus caprinus (Leguminosae) were investigated; more than 30 glycosides were found in leaf material, based on the aglycones kaempferol, quercetin and their methylated derivatives. Among them 14 compounds were found in significant amounts and showed a contrasting distribution. They could be ordered into three groups: polyglycosides, acylated polyglycosides and methylated polyglycosides. The distribution of these compounds was studied within a large collection of individual plants harvested in Tunisia; the results showed a relationship between metabolic trends and ecological diversification.