The InnerWorld of Passionflowers showcases the work of Marcelo Dornelas and his research group at Universidade Estadual de Campinas in Brazil.

When the first passionflowers were described, the naturalists of that time were so mesmerized by their unusual floral organs that they associated them to religious symbols related to the Passion of the Christ, hence the name: “passionflower”. Since then many artists and botanists described the diversity of shapes and sizes of these unusual flowers and their intriguing floral organs. Modern techniques such as x-ray tomography and Optical Projection Tomography allowed a more detailed description and the study of these unique floral organs such as the corona, which is a structure resembling a crown of filaments; or the androgynophore, a structure in the shape of a column that contains the reproductive floral organs. Some passionflower species, like the one producing the passionfruit, are pollinated by carpenter bees. The flowers of these species show large coronas with long filaments, that help the bee to push itself to center of the flower, where a relatively short androgynophore column is adapted to transfer pollen grains from the flower to the bee and vice-versa, while the bee reaches the nectary chambers to receive its reward. On the other hand, some passionflower species are pollinated by bats. These have night-opening, white flowers with a corona containing relatively short filaments and a long curved androgynophore. Both structures are adapted to perfectly match the shape of the head of a bat. Finally, some passionflowers are pollinated by hummingbirds. These brightly colored flowers have even shorter corona filaments and a long straight androgynophore, which efficiently transfer pollen grains from and to the hummingbird, as it reaches the nectary chamber in the inner parts of the flower. From the earliest descriptions to today´s studies, passionflowers have awakened a different kind of passion: the passion for science and eagerness to uncover the secrets of development and evolution.

Explore the inner world of Passionflowers further on these pages: