When hung over a threshold at Christmastime, a sprig of mistletoe is a matchmaker; in the wild, the plant is a parasite known as the "thief of trees." Now, thanks to a recent study in Australia, mistletoe has a new reputation: forest savior. Field research indicates it's actually a beneficial plant, critical to a healthy ecosystem.
Despite its efforts to keep a low profile—lurking, as it tends to do, deep in Southeast Asia's undisturbed rainforests—the Rafflesia arnoldii has international notoriety. Its detractors might call it a hulking, smelly parasite, and they would not be wrong. It's the world's largest flower, and it smells like rotting meat.