There are several varieties of Joe-Pye Weed, but the most common one around here is Eupatorium fistulosum. It is a tall, slim plant 5-10 feet in height, with whorls of dark green, spear shaped leaves. What will catch your eye is the dome-shaped cluster of dull pink flowers that bloom from July into October. It is very common in our area, and tends prefers moist areas.
The plant was named after an herbalist named Joe-Pye, a 19th century promoter of Native American cures for ailments. Joe-Pye Weed is considered a medicinal plant, and has other names that refer to its use, including Gravel Root and Kidney Root (for treating kidney stones). It has a long listing of reported medicinal uses, including treating bed wetting, dropsy (fluid retention), gout, rheumatism, impotence, asthma, and chronic cough.
Though considered a weed, the English have been using Joe-Pye as a cottage garden flower for many years. Because of its height it is often used as a background border behind shorter plants. It attracts a variety of butterflies, including the Swallowtail, Monarch, and Pearl Crescent. So you might want to consider going native and putting Joe-Pye in your landscape. It likes a sunny spot with moist soil, but can tolerate dry conditions if you keep it watered and incorporate some organic matter into the soil.