Assertion: bilberry's leaf | /r/MadeOf | tannin
Facets:
Source sentences:
text: The leaves contain tannins, flavonoid glycosides, neo-myrtillin, arbutin, hydroquinone, organic acids, and the trace mineral manganese.
text: Bilberry is thought to work for diabetes because its leaves contain polyphenols, tannins, flavonoids, and a high concentration of chromium.