Rice (Oryza sativa) is probably a native of south Asia, and it has been cultivated on that continent for more than 5,000 years. The natural habitat of rice is tropical marshes, but it is now cultivated in a wide range of subtropical and tropical habitats.
If rice is being cultivated under flooded conditions, its seeds are germinated, grown until they are about 6-12 in (15-30 cm) tall, and then out-planted into the sediment in shallow water. In Asia, this cultivation system is known as paddy. A variant of this system is also used in the southern United States where fields are flooded to plant and grow the crop and then drained for optimal ripening and the harvest. Rice can also be cultivated under drier conditions, called "upland" rice, although the soil must be kept moist because the species is intolerant of drought. On moist, fertile sites in some parts of tropical Asia, two to four rice crops can be harvested each year, although this eventually could deplete the soil of its nutrient capital.
Rice is mostly eaten steamed or boiled, but it can also be dried and ground into a flour. Like most grains, rice can be used to make beer and liquors. Rice straw is used to make paper and can also be woven into mats, hats, and other products.