2. Lemon is a dicotyledonous plant belonging to Rutaceae and Citrus. Lemon is also called lemon fruit, foreign lemon and beneficial mother fruit. Small trees with little or no thorns, dark purple leaves and buds, thick papery leaves, oval or ovoid. Flowers axillary or rarely clustered. The fruit is oval or ovoid, with thick peel, usually rough, lemon yellow, sour to very sour juice, small seeds, ovoid and sharp; Seed coat is smooth, cotyledons are milky white, usually single embryo or multi-embryo. The flowering period is April-May, and the fruiting period is September-165438+1October.