The Jerusalem artichoke (Helianthus tuberosus), also called the sunroot, sunchoke, earth apple or topinambour, is a species of sunflower native to eastern North America, and found from Eastern Canada and Maine west to North Dakota, and south to northern Florida and Texas. It is also cultivated widely across the temperate zone for its tuber, which is used as a root vegetable
It is a herbaceous perennial plant growing to 1.5–3 metres (4 ft 10 in–9 ft 10 in) tall with opposite leaves on the lower part of the stem becoming alternate higher up. The leaves have a rough, hairy texture and the larger leaves on the lower stem are broad ovoid-acute and can be up to 30 centimetres (12 in) long and the higher leaves smaller and narrower.
The flowers are yellow, produced in capitate flower heads which are 5–10 centimetres (2.0–3.9 in) in diameter, with 10–20 ray florets.
The tubers are elongated and uneven, typically 7.5–10 centimetres (3.0–3.9 in) long and 3–5 centimetres (1.2–2.0 in) thick, and vaguely resembling ginger root, with a crisp texture when raw. They vary in color from pale brown to white, red or purple
The tubers are sometimes used as a substitute for potatoes: they have a similar consistency, and in their raw form have a similar texture, but a sweeter, nuttier flavor; raw and sliced thinly, they are fit for a salad. The carbohydrates give the tubers a tendency to become soft and mushy if boiled, but they retain their texture better when steamed. The inulin cannot be broken down by the human digestive system, which can cause flatulence and, in some cases, gastric pain