Helianthus tuberosus, L.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1976, Flora Europaea. Volume 4. Plantaginaceae to Compositae (and Rubiaceae), Cambridge University Press : 141

2. H. tuberosus L. , Sp. Pl. 905 (1753).

Perennial; stems 1—2-8 m, scabrid-hispid or glabrous, usually branched above. Rhizomes tuberous. Leaves 10-25 x 7-15 cm, ovate, acuminate, coarsely serrate, scabrid above, whitish-pubescent beneath, narrowed into a winged petiole, the upper not much smaller. Capitula 4-8 cm in diameter, several, erect. Involucral bracts at least as long as the diameter of the disc, more or less patent, lanceolate, acuminate, ciliate, dark green. Receptacle convex. Ligules 30-40 mm. Inner florets yellow. Achenes 5-6 mm, glabrous or hairy. Cultivatedfor its edible tubers (Jerusalem artichokes) and naturalized, mainly in C. Europe. [Al Au Cz Ge He Ho Hs Hu It Ju Rm Rs (C).] (North America.)