Flavonoid chemistry of Coreopsis grandiflora (Compositae)

The leaf flavonoid chemistryof Coreopsis grandiflora, which includes var.harveyana, var.longipes, var.saxicola and the typical var.grandiflora, is quite uniform with 6-hy-droxyquercetin 7-O-glucoside, luteolin 7-O-glucoside, marein-maritimein chal-cone-aurone pair and lanceolin-leptosin chalcone-aurone pair as consistent com-ponents. Flavonoid data lend support to the hypothesis that the hexaploid var.longipes originated from parents which would be included withinC. grandiflora, i.e., there is no evidence that other species were involved in its formation. One population of var.grandiflora and several collections of var.saxicola contain additional flavonoid components in the form of flavonol 3-O-glycosides. In nearly all instances the additional compounds are attributable to hybridization withC. lanceolata orC. pubescens because these flavonols are characteristic of these two species and morphological considerations also suggest it. Flavonoid chemistry supports the treatment of var.saxicola as a variety ofC. grandiflora rather than as a distinct species.