Mimulus lewisii and M. cardinalis are closely related, but M. lewisii is pink-flowered and pollinated by bumblebees while M. cardinalis is
red-flowered and pollinated by hummingbirds. Pollinator preference is
believed to he due in part to the difference in flower color between
these two species. Ten anthocyanins are characterized from M. lewisii
and M. cardinalis petal lobes by high performance liquid chromatography
(HPLC) and electrospray tandem mass spectrometry (ES/MSMS). Total
anthocyanin concentration in the petals of M. cardinalis is
approximately twice as high as that in M. lewisii, and that this
difference can be accounted for by the presence of two pelargonidin
biosides, probably rhamnohexosides, unique to M. cardinalis. Cyanidin
biosides comprise 33\% of all the anthocyanins in M. lewisii, but only
2.4\% of those in M. cardinalis. (C) 1997 Elsevier Science Ltd.