We have isolated and identified seven flavonoid compounds from the foliar extracts of Heloniopsis orientalis, a member of Liliaceae, which is habituated at Namhansanseong and Maranggol (Jinburyung). All are glycosylated derivatives of the flavonols isorhamnetin, kaempferol, and quercetin. Among them, quercetin 3-O-galactoside is the major compound, while isorhamnetin 3-O-arabinosylgalactoside, isorhamnetin 3-O-digalactoside, kaempferol 3,7-O-galactoside, kaempferol 3-O-arabinosylgalactoside, kaempferol 3-O-glycoside, and quercetin 3-O-arabinosylgalactoside are present in smaller amounts. Although the two populations do not differ significantly in their overall flavonol profiles, their relative amounts indicate that flavonoid levels, especially for isorhamnetin, are geographically controlled and specifically depend on the origin of the individual population.