Of the orchid genus catasetum, Charles Darwin wrote: "I never was more interested in any subject in all my life than in this of Orchids." The male flowers in this genus evolved an unusual pollination program. They propel a package of pollen onto the backs of visiting bees. The bees endure the blow (which would be like a 150-pound person getting hit with a few bowling balls) in exchange for orchid aromas that the bees use to attract mates.