Andromonoecy is a rare sexual system in which plants produce both bisexual and male flowers. In this paper we present the results of a quantitative study on the relative production of male and bisexual flowers in Prunus caroliniana (Rosaceae). Ten individual trees located in Statesboro, Georgia were sampled to determine the relative production of male and bisexual flowers. Approximately 80% of the 5,000 sampled flowers were male. Male flower production at the whole plant level ranged from 38% to 98%. Thus, some individual plants were reproducing almost exclusively via male function and pollen donation while others presumably had more mixed mating patterns. The patterns of sex expression revealed here suggest that subtle changes in floral morphology associated with andromonoecy may be occuring in many more taxonomic entities than is currently believed.