The California poppy (Eschscholzia californica Cham.) is a member of the Papaveraceae family that produces various types of benzylisoquinoline alkaloids (BIAs), e.g., benzophenanthridine, pavine, and protoberberine-type alkaloids. The major alkaloid biosynthesis pathways and biosynthetic enzymes of these BIAs have been characterized at the molecular level, and cytochrome P450s have been found to be involved in the diversification of BIA metabolism. In this issue, Hori et al (on pp. 222-233) report the draft genome sequence of California poppy and characterized the diversification of the CYP82 family and their functions in the evolution of BIA biosynthesis.