Joe Pye Weed

This is one of my favorite North American wildflowers -- Eutrochium purpureum (formerly Eupatorium), commonly known as Joe Pye Weed.  Eutrochium is a tall (6-7') summer flowering perennial, typically with pink flowers as seen below.  Part of the reason that this plant is now Eutrochium and not Eupatorium is because the former has whorled leaves (indeed, trocho is Greek for wheel-like, thus whorled) and the latter has opposite leaves. Both genera remain in the Asteraceae family.

Below, a white flowering variety, less common than the purplish pink flowers.  One way to distinguish E. purpureum from E. maculatum (these plants are often confused) is the presence of pink spots along the entire stem of E. maculatum, as opposed to the clear green or purple stems on E. purpureum.

Joe Pye weed is a pretty terrific common name, too.  It's named for a Native American who was known by colonists as Joe Pye.  As legend goes, he used the roots of this plant to aid a colonist who was ill with typhus.  The plant induced sweating which broke his fever. The plant was also used by Native Americans as an ailment to "breakbone fever" (which is now known as dengue fever), thus another common name of boneset (though boneset is usually considered the common name for Eutrochium perfoliatum, a close relative). 

You need a fair amount of real estate to use this plant, as large as it gets.  But if you have the space, it's a great addition as it provides habitat to bees, butterflies and birds.