Flavonoids of Lupinus Sects. Platycarpos and Lupinellus (Fabaceae)

All members of Lupinus section Platycarpos, here taken to include L. kingii and section Lupinellus which consists of L. uncialis, have been examined for their flavonoid content. A rich array of 0-glucosyl and C-glucosyl flavones was found. Flavonoid profiles of the entire group support our earlier conclusion, based upon a smaller sample, that the annual lupines with connate cotyledons exhibit a unique array of pigments. Furthermore, the distribution of these compounds clearly supports an earlier view of C. P. Smith that two groups of species should be recognized. His group Microcarpi is characterized by accumulating major amounts of C-glucosylflavones while his Pusilli exhibits major amount of 0-glucosylflavones. Lupinus kingii, although a member of Pusilli on the basis of its floral features, and L. uncialis exhibit flavonoid profiles somewhat different from the other groups. In our survey of North American members of the genus Lupinus (Nicholls and Bohm 1983) we examined six species of section Platycarpos (Watson 1873). Since completion of that study we have acquired material of the remaining species of the section as well as additional spec- imens of most of the other taxa included in the original study, which allowed a complete reex- amination of the entire group. Species -newly analyzed in the present study are L. brevicaulis, L. odoratus, L. shockleyi, and L. subvexus. Watson (1873) established Lupinus sections Platycarpos and Lupinellus to accommodate an-