*Helianthus tuberosus L.

Leaves mostly opposite, ovate to oblong, serrato-dentate, up to 16 cm long, 5–8 cm wide; petioles winged. Rays yellow. Disc florets yellow. Heads numerous in a corymb, mostly 5–8 cm diam. Erect perennial up to 3 m high, with edible root tubers. Occasional near habitation. Introd. from America. Fl. summer. Jerusalem Artichoke