Smallanthus is a genus of sunflower like plants in the Asteraceae.
Smallanthus sonchifolius, (syn. Polymnia edulis, P. sonchifolia) is known as Yacón and is grown for its large edible tuberous roots, similar in flavor to jicama (Pachyrhizus erosus). It is native to South America and grown as a food crop in much of its range. It spreads by rhizomes, which send up new shoots. Under the new shoots, new tubers form. The flowers are small and sunflower like, and it is loosely related to Helianthus tuberosus.
Pictures show plants grown by Martin Bohnet, with the roots of a nameless white and a red cultivar "Morado". Freshly harvested they tasted somewhat bland with a hint of Dahlia, but are said to sweeten up in storage. Why the yield is fine unter conditions in Southern Germany, the plants usually don't flower here.