As I've written many times before, plants do not exist to serve humans. They exist so they can exist. In order to do so, they become factories for all kinds of toxic chemicals to ward off whatever varmint is in the mood to eat them.
essential oils
Since essential oils, such as lavender and tea tree oils have been all over the news for allegedly causing moobs, and I found that even my own colleagues at ACSH (1) didn't really know what the term "essential oil"