Daidaihua, also known as: lime, Huiqingcheng, Daidai. Latin name: Citrus aurantium L. It belongs to the family Rutaceae and citrus. It is a small tree with dense branches and leaves and many thorns. The thorns on the leggy branches are up to 8 cm long. With its whirling green leaves and hanging golden fruits, it is a rare gem among domestic flowers. The fruits of Daidaihua are dark green at first and turn orange-yellow when mature. They do not fall off and turn green again in the following spring and summer, so they are called "green oranges". If cared for properly, the fruit can last until the third year, so it is also called "Dai Dai".