The Jerusalem artichoke (Helianthus tuberosus), also called sunroot, sunchoke, wild sunflower, topinambur, or earth apple, is a species of sunflower native to central North America.It is cultivated widely across the temperate zone for its tuber, which is used as a root vegetable ...The Jerusalem artichoke (Helianthus tuberosus), also called sunroot, sunchoke, wild sunflower, topinambur, or earth apple, is a species of sunflower native to central North America.It is cultivated widely across the temperate zone for its tuber, which is used as a root vegetable. The flowers are yellow and produced in capitate flowerheads, which are 510 cm (2.03.9 in) in diameter, with 1020 ray florets and 60 or more small disc florets. (resource from Wikipedia);