The other day I when I was sitting on the porch at my parents’ house, the smell of gardenias hung heavy in the air, and I breathed it in deeply. For those of you who aren’t familiar with these iconic southern flowers, the smell is sickeningly sweet, in much the same way as old-fashioned roses whose blooms perfume the air with strong fragrance, enough to inspire perfumes and poems. Yet the fragrance of gardenias is nothing like roses. Gardenias...