BIOCHEMICAL HETEROPHYLLY AND FLAVONOID EVOLUTION IN NORTH AMERICAN POTAMOGETON (POTAMOGETONACEAE).

Morphologically heterophyllous species of Potamogeton also commonly display biochemical heterophylly with respect to flavonoid compounds. Generally, floating leaves contain an assortment of flavonoids, whereas submersed leaves often exhibit reduced flavonoid profiles. In strictly submersed (homophyllous) species, two patterns occur.