2. Osmunda japonica is a common perennial dicotyledonous plant with slender vines and creeping stems, which can form tuberous roots. Tuberous root, anaerobic respiration produces lactic acid, with white or red skin and yellow-white meat. Besides being used as food, it can also be used to make sugar and alcohol.
Osmunda japonica originated in Peru and Mexico, but it didn't spread until Columbus discovered the New World. China is the country with the largest planting area and the largest output in the world, mainly distributed in Huanghuai Plain, Sichuan Basin, the middle and lower reaches of the Yangtze River and the southeast coast, among which Shandong, Sichuan, Henan, Guangdong, Jiangsu and Anhui are more. The planting area of Polygonum cuspidatum is gradually decreasing, while the Philippines uses Polygonum cuspidatum as energy in the development of alcohol industry, and the planting area has increased.
Osmunda japonica is one of the main plant sources of vitamin A. A bowl of 225g cooked sweet potato can provide calories 1 155kJ, protein 15g, carbohydrates 29.5g, calcium 18mg, phosphorus 20mg, iron 0.4mg, carotene 30mg and vitamins. It can be eaten in many ways: raw, steamed, boiled, simmered, porridge cooked, cut, dried, ground and brewed with sugar. Leaves can be used as vegetables, and skins and roots can be used for domestic animals such as pigs, cows and rabbits. The latest research shows that Rhizoma Osmundae also has the function of preventing atherosclerosis and cancer.