Tall and stout Telekia speciosa,  or Heartleaf Oxeye Daisy, is an impressive perennial daisy (now synonymous with Bupthalmum speciosum) with huge, heart-shaped leaves and large, deep golden flowers that really stand out in the perennial garden.  Telekia grows from four to six feet tall and blooms for quite a while in full sun.  It is particularly suited to wetlands or isolated places, as it spreads.  Telekia speciosum is often confused with Inula helenium (Elecampane) which, I think, may have once also been referred to Bupthalmum.  Zones 5-8.  (Photo by sarefo and licensed by http://creativecommons.org/licenses/by-sa/3.0/deed.en, public domain)