Otherwise known as Lemon Verbena, which in turn is known to me as *THE* best herb to turn into a tea infusion ever.
The following I've lifted right out of the Lemon Verbena entry in The Southern Living Garden Book that my sister gave me not too long ago.
"this plant is prized for its leaves, which scent the area around them with a citruslike fragrance. . . . When you read of the scent of verbena in literature about the antebellum South, lemon verbena is the plant being described. . . . The long, shiny leaves add lemony flavor to teas and iced drinks."
According to my book, the upper south extends into the lower half of St. Louis. Good to know.