This plant smells good. Take a flower and smoosh it a bit and smell it, it's very lemony. Take a leaf and crush it up, it smells like citronella.
According to Wikipedia this plant was discovered by Peter Collinson, an English botanist. It also says that the Native Americans used it as a medicinal. I guess the Native Americans don't count when it comes to discovering things, sort of how Christopher Columbus "discovered" America.