Helianthus is a genus of the family Asteraceae. It is a genus exclusive to North America and Mexico with approximately 52 species. economically it is important as a source for sunflowers (Helianthus annuus) or the Jerusalem artichoke (Helianthus tuberosus). Plants can be annuals or perennials.
Helianthus tuberosus is a tuberous species, also known as Jerusalem artichoke. The tubers can be rather large and is grown for food in Europe and some parts of North America. According to the USDA, it is present in most states except Alaska, Hawaii, New Mexico, Arizona, and Utah. Flowers are typical of wild Helianthus with multiple showy golden ray florets and a center of disk florets. In discussions on the PBS list, this species has been given the name 'sunchoke'.
Pictures below by David Pilling showing the foliage and the tubers. His experience is that you may buy some tubers from the grocery store, plant them and get a reliable seven foot high clump of foliage every year, but (at least in the North West of England) you won't get any flowers.