Windspiel is a German word meaning wind play, and it refers to the way the wind moves the blooms of this giant plant that can grow to 7 feet tall. A clump-forming ornamental grass that prefers full sun, it has linear green leaves that turn yellow in the fall and 15- to 20-inch purple flower panicles that bloom from June to October. Planted as a specimen or in a mass, it lends elegance to the garden.