Christmas cactus is a type of jungle cactus that grows naturally in the Brazilian rainforests. For gardeners, they are cultivated as a houseplant and manipulated to bloom during the holiday season.

Original broadcast date: July 15, 2022. "The birds and the bees" may be a euphemism for human reproduction, but procreation of actual winged animals is far wilder. This hour, TED speakers explore how ...