Passiflora Bird Pollination

Many passionflower species are pollinated by birds, mostly by hummingbirds. All hummingbird-pollinated passionflowers have in common short corona filaments and a long straight androgynophore. Some flowers have reflexed petals not to disturb the approximation of the birds. Hummingbirds are very fond of tube-shaped flowers. Therefore some passionflowers have “tubes” formed by the fused base of sepals and petals or by the fusion of the corona filaments. We combine the use of X-ray microtomography images with traditional plant physiology and plant molecular biology tools to study the development of these flowers. The InnerWorld of Passionflowers showcases the work of Marcelo Dornelas and his research group at Universidade Estadual de Campinas in Brazil.

Passiflora coccinea is a hummingbird-pollinated passionflower. The movie shows X-ray microtomography images obtained from freshly collected flowers and flower buds. Passiflora coccinea is native to the Central Amazonian region and its flowers are pollinated by hermit hummingbirds of the genus Phaethornis.

This movie shows X-ray microtomography images of flowers of Passiflora sanguinolenta, and Passiflora citrina, both hummingbird-pollinated passionflowers native to the islands of the Caribbean. These species belong to the Xerogona section of the subgenus Decaloba. These flowers are quite curious as they show a movement of the androgynophore induced by touch. It is believed that this feature would enhance pollination efficiency.

The flower of Passiflora tulae, a passionflower species native to Central America that we successfully cultivate in Brazil to study hummingbird-pollination of passionflowers.