Heterostyly, a complex and elegant breeding system, is defined as the occurrence in a species of two or more floral morphs that exhibit reciprocal herkogamy. Heterostyly is often associated with ancillary physiological and structural characters, such as self- and intramorph-incompatibility (SI) and pollen and stigma polymorphisms.  The breeding system has evolved multiple times among the angiosperms, but we are still trying to understand the manner in which heterostyly can arise and how heterostyly differs in each origin.  My students and I are studying floral developmental patterns of heterostyly and placing these data in an evolutionary context in order to better understand the origin of this breeding system.