A group of aromatic, oxygen-containing, heterocyclic pigments widely distributed among higher plants. They constitute most of the yellow, red, and blue colors in flowers and fruits. Exceptions are the carotenoids. The flavonoids include the following subgroups: (1) catechins; (2) leucoanthocyanidins and flavanones; (3) flavanins, flavones, and anthocyanins; and (4) flavonols.For details consult specific entries.