Recognizable by their iconic fragrant white flowers, Osa pulchra is one of the rarest plants growing in our Conservatory. This plant’s large, pendulous, trumpet-shaped flowers truly make it a sight to be seen. Belonging to the Rubiaceae (coffee) family, Osa pulchra is the only species in its genus, Osa. The species’ name comes from the Osa Peninsula in Costa Rica and the word pulchra, which means beautiful in Latin.
The Osa pulchra species is so rare that it was once thought to be extinct. There are only three known populations of this endangered species in the wild: one in Panama and two in Costa Rica, where there are around only 30 remaining individuals. Habitat destruction, along with the species' narrow distribution, have contributed to the species’ scarcity. Now, it can be found growing in a select few conservatories across the world, like ours here in Davis.
Osa pulchra is difficult to propagate. While a perfect flower (both male and female reproductive parts), the plant cannot self-pollinate, and a second plant is needed. In their natural habitat, Osa pulchra’s fragrant white flowers are thought to attract bats at night. As the bats travel from flower to flower, the pollen that sticks to their faces is transferred to new plants, resulting in pollination.
The conservatory has only one clone, making seed production impossible. We have been able to produce a second plant by stem cuttings, but this itself is difficult.