Helianthus maximilliani--Maximillian's Daisy is a tall (3-8 feet) perennial sunflower with yellow flowers to 3 in. across, clustered on upper ˝ of stem; leaves are grayish-green and rough to the touch, often folded and curving downward.   The plant is rhizomatous and hardy.  Light yellow blooms open in late Aug. – Oct. in zone 5.  Butterflies and other critters are attracted to the nectar.  Seed eating birds such as goldfinch & chickadees relish the seeds in winter.  Don't fertilize this plant or it will be too much!