Synonyms are H. tuberosus var. fusiformis., Helianthus tuberosus L.

Common names are Jerusalem Artichoke, Sunroot (Eng.); Girasole, Topinambour (Fr.); Alcochofa de Jerusalem, Aguaturma (Sp.); Erd Topinambur, Erdartischocke (Ger.); Aardpeer, Topinambour (Neth.); Hatichuk, Hathipick (Ind.); Cotufa (Philipp.); Brahmokha (Bangl.); Kiku-imo (Jap.).

Cultivars is in America.

Native to North America and introduced into Europe in the early seventeenth century. This form of artichoke is now widely distributed throughout temperate and tropical regions.

Endive was cultivated in Egypt over 2000 years ago and was distributed from there throughout Europe and Asia. It is now cultivated in the Caribbean area, the Philippines, Central and West Africa.

An annual or biennial herb. Roots: fibrous. Stems: condensed, round, rarely more than a few cm in length. Leaves: in dense rosettes, light or dark green; form very variable, being divided, curled or broad; mature leaves have a bitter taste. Flowers: pale blue, rarely seen in tropical areas; flowering stem up to 1 m in height. Seeds: with pappus.

Relatively tolerant to a wide range of climatic and soil conditions although well-drained sandy loams, with a pH of 6.0-6.8 are generally considered preferable. Cultivars which are specifically adapted to tropical environments have been hybridised or selected for many ecological regions. Many are tolerant to high day temperatures of up to 30C and short days, although the most suitable range for most cultivars is 15-20C. High temperatures often result in premature flowering, stunted leaf growth and bitter tasting leaves. At low elevations in high temperature areas, some cultivars do not form solid heads; they tend to flower precociously and seed without forming the normal number of rosette leaves. Cultivars have been selected which do not readily form flowering stems at high temperatures. Elevations above 1000 m provide good conditions for optimum growth. Seeds require a period of dry storage before sowing and some cultivars which have been stored at high temperatures have a requirement for exposure to light before dormancy is broken. The optimum germination temperature is 25C; above this temperature, germination percentage falls rapidly due to an inhibition of gaseous diffusion and a consequent shortage of oxygen. Gibberellic acid (GA3) has been found to overcome dormancy induced by high temperatures. Viability is rapidly lost in moist atmospheres at high temperatures. Daylength variation does not appear to affect development to any significant extent.

Propagation is by tubers; the size of the tuber planted is often related directly to the yield. Tubers, or portions of tuber (setts) with 2-3 buds, weighing approximately 56 g, are planted at a depth of 2.5-5 cm, usually on 300-500 kg/ha of tubers or setts are required. Beds are often mulched directly after planting to conserve soil moisture and plants are sometimes earthed up when tuber development begins. Supplementary applications of both nitrogen and potassium are likely to be required since the crop demand for these minerals is relatively high.

Most heading cultivars mature within 60-85 days from transplanting but the loose leaf types may be ready for harvesting within 35-50 days from planting. Harvesting during the early part of the day is preferable, particularly in hot weather. Yield: Approximately 5-15 t/ha, individual plant weights varying according to cultivar and climate. Seed production: Plants which become mature and are allowed to flower will normally form viable seed which can be stored for up to 4 years at a relatively low temperature and humidity. Premature flowering may be reduced by light shading and regular irrigation. Most cultivars are usually completely self-pollinated. With mature plants with solid hearts, the removal of the hearted leaves to expose the growing point will accelerate flower head emergence and increase seed yield. A seed yield of approximately 120 kg/ha can be expected.

The leaves should be fresh and crisp, free of diseases or pests and either green or cream, if blanched. The central leaves should be healthy, with no discoloration. The heads are normally washed immediately after harvest. Wilting can be reduced by spraying with water but complete enclosure within plastic wrappers or bags should be avoided, the top should be left open. At 0C the storage life is about 20 days.

The tubers are eaten as a cooked vegetable, being often added to soups and stews; they may also be pickled.