Flavonol Glycoside Variation in Diploids of the Claytonia perfoliata Complex (Portulacaceae)

Abstract

Three allopatric, morphologically distinct diploid species and their auto- and allopolyploid derivatives constitute the Claytonia perfoliata complex. Diploid C. rubra synthesizes kaempferol-3-O-glucoside, kaempferol-3-O-arabinosylglucoside, and novel kaempferol-3-O-rhamnosylarabinosylglucoside. Claytonia perfoliata dip- loids yield the same array of glycosides but both kaempferol and quercetin are glycosylated. Unlike the autogamous C. rubra or C. perfoliata, the facultatively xe- nogamous diploid C. parvflora makes abundant diglycosides of kaempferol and quercetin including rhamnosylglucosides, arabinosylglucosides, and a glucosylglu- coside. In all three taxa flavonol-3-O-glycosides show little interpopulational varia- tion and are localized in floral tissue. Flavonoid data support a multi-species general- purpose classification for the C. perfoliata complex. Considerable descriptive information that unravels the morphological and cytological complexity of the myriad of forms attributable to the Claytonia perfoliata complex has been published (Miller 1976, 1978). Dip- loid populations of Claytonia parviflora Hook., C. rubra (T. Howell) Ti- destr., and C. perfoliata Willd. have been clearly distinguished on mor- phological grounds. Each diploid occupies a different, well-defined habitat. Diploid, annual C. perfoliata is autogamous and widely scattered in moist, naturally disturbed sites over a 3000 km geographic range from low elevations in the California Coast, Transverse, and Peninsular ranges, through mid-elevations in the Sonoran Desert mountains of southern Arizona, to high elevation coniferous forests of the Sierra Madre Occidental and Trans-Mexican Volcanic Belt. High polyploids of this species occur as a disjunct population in the Guatemalan Highlands. In contrast, diploids of C. parviflora are facultatively xenogamous annuals that occur sporadically within the foothill woodland belt of the California Sierra Nevada. A third diploid, C. rubra is obligately autogamous and grows in disturbed coniferous and sagebrush woodlands or along water- courses in the western Rocky Mountains, northern Great Basin, Cascade Range, Klamath Mountains, and Sierra Nevada. This species, at the dip- loid level, reaches a southern limit at high elevations on Mt. Pinos in the California Transverse Ranges. This paper presents evidence that each diploid taxon displays a distinct