1. Lemon is cool. Lemon (scientific name: Citrus limon (L.) Burm. F.) belongs to the genus Citrus of Rutaceae, a dicotyledonous plant. Lemon is also called lemon fruit, foreign lemon, beneficial mother fruit and so on. Small trees with few or nearly no thorns, dark purple leaves and flower buds, thick papery leaves, oval or oval. Single flowers axillary or few flowers clustered. The fruit is oval or ovoid, with thick peel, usually rough, lemon yellow, sour to very sour juice, small, ovoid and pointed seeds; Seed coat is smooth, cotyledons are milky white, usually single or with multiple embryos. The flowering period is April-May and the fruiting period is September-November.

2. Lemons are produced in the south of the Yangtze River in China, originated in Southeast Asia, and mainly produced in the United States, Italy, Spain and Greece.

3. Because of its extremely sour taste, lemon is the favorite food for pregnant women, so it is called beneficial mother fruit or beneficial mother and child. Lemon is rich in citric acid, so it is known as "citric acid warehouse". Its fruit juice is fleshy and crisp, with a strong aroma. Because of its sour taste, it can only be used as a superior seasoning to prepare drinks, dishes, cosmetics and medicines. In addition, lemon is rich in vitamin C, which can relieve phlegm and cough, promote fluid production and strengthen the stomach. For bronchitis, whooping cough, loss of appetite, vitamin deficiency, heatstroke and polydipsia, it is the bane of scurvy.