The Jerusalem artichoke (Helianthus tuberosus), also called 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 The flowers are yellow and produced in capitate flowerheads, 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 artichoke contains about 10% protein, no oil, and a surprising lack of starch 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. In Baden-Württemberg, Germany, over 90% of the Jerusalem artichoke crop is used to produce a spirit called "Topinambur", "Topi" or "Rossler". By the end of the 19th-century Jerusalem artichokes were being used in Baden to make a spirit called "Jerusalem artichoke brandy," "Jerusalem artichoke", "Topi", "Erdäpfler" "Rossler" or "Borbel." Jerusalem artichoke brandy smells fruity and has a slight nutty-sweet flavour. It is characterised by an intense pleasing earthy note. The tubers are washed and dried in an oven before being fermented and distilled. It can be further refined to make "red rossler" by adding Common Tormentil, and other ingredients such as currants, to produce a somewhat bitter and astringent decoction. It is used as digestif as well as a remedy for diarrhea or abdominal pain.