Tobacco

An annual herb 1–2 m tall (up to 3 m under good conditions), sticky-hairy all over; stems are thick and sparingly branched. The very large leaves spiral around the stem; blades are ovate-elliptic to obovate, pointed, up to over 50 cm long, dotted with aromatic glandular hairs; young leaves are harvested for tobacco products. The inflorescence is a terminal panicle; flowers are long-tubed with 5 spreading lobes, white to pink, 5 calyx lobes, fragrant towards evening. The fruit is an ovoid capsule packed with very small seeds (a single plant can yield hundreds of thousands). The leaves contain the alkaloid nicotine, as do older leaves and stems. Vietnamese thuốc lào is made from a different species (Nicotiana rustica) with higher nicotine.\n

Nicotiana tabacum is the cultivated species, thought to be a hybrid of Nicotiana sylvestris and N. tomentosiformis (possibly also N. otophora), native to the Andes — Bolivia and northwestern Argentina. American peoples used tobacco leaves for thousands of years; after Columbus the habit spread to Europe in the 16th century and then worldwide. Today leaf tobacco is grown in over 100 countries; China produces roughly 40% of world output (FAOSTAT), followed by India, Brazil and African countries such as Zimbabwe and Malawi. In Vietnam, golden flue-cured tobacco is grown mainly in Ninh Thuận (hot, sandy soils), Cao Bằng–Lạng Sơn and Gia Lai; thuốc lào in many midland provinces. After harvest leaves are cured, fermented, shredded or wrapped. Smoking is a major cause of lung cancer and cardiovascular disease — countries tighten advertising rules and put health warnings on packs.\n