Many workers have considered Pistia an evolutionary link between the Aroids and the Lemnaceae. The Lemnaceae have a rich flavonoid chemistry which becomes less complex as one follows the morphological reduction from Spirodela to Lemna and thence to Wolffiella and Wolffia. Pistia contains large amounts of two di-C-glycosylflavones of the vicenin and lucenin type plus two unidentified compounds which are probably their derivatives, lesser amounts of the anthocyanin cyanidin-3-glucoside and a luteolin-7-glycoside, and traces of the mono-C-glycosylflavones vitexin and orientin. Although there is no close correspondence between the specific flavonoids accumulated by Pistia and those found in the morphologically more complex members of the Lemnaceae, Pistia appears to have the biochemical pathways to most flavonoid types found in the Lemnaceae. This is in agreement with the concept that the Lemnaceae may have arisen from a Pistia-like ancestor. © 1977.
Zennie, T. M., & McClure, J. W. (1977). The flavonoid chemistry of Pistia stratiotes L. and the origin of the lemnaceae. Aquatic Botany, 3(C), 49–54. https://doi.org/10.1016/0304-3770(77)90003-1