The floral traits in Bignoniaceae are claimed as precise determiners of specialized pollination systems. Here, we investigated how such floral traits ensure a highly specialized interaction between Jacaranda rugosa and medium-sized bees by examining visual, and olfactory signaling, as well as mechanical fit to pollinating bees. We also report the efficiency of the system by fitness measures (pollen delivery from anthers; pollen deposition on stigma; fruit and seed set). Jacaranda rugosa probably attracting bees through chromatic and achromatic contrasts of staminode with corolla and pollen mimicry, and floral volatile compounds that are common to other bee-pollinated systems. Fundamental and realized accuracy ensure tight mechanical fit to medium-sized bees. While the natural female component is strongly limited, promoting lower fruit set than pollinated flowers, the floral morphology seems to ensure high male fitness by pollen transfer. Our results demonstrate that floral traits of J. rugosa promote a specialized system for pollination by medium-sized bees, and this process is likely to happen in other species of Bignoniaceae or flowers with similar traits. [ABSTRACT FROM AUTHOR]