1. Toi Dai flower is a citrus plant of the Rutaceae family. Toi Dai flower is also called Daidai flower, "daidai", which means passed down from generation to generation. It likes a warm and humid climate, is not cold-tolerant, and its seedlings are afraid of frost. The flower buds are picked from May to June. The young fruits are called Citrus aurantium fruit, and the mature ones are called Citrus aurantium kettle.

2. Toi Toi flower, evergreen shrub or small tree, 5-10m high. The leaves are leathery, oval to ovate-oblong, 5-10cm long, 2.5-5cm wide. The flower buds are slightly oblong, 1-1.5cm long, 6-8mm in diameter, with 5 petals, yellow-white or light yellow. Brown, with numerous pollen grains, light yellow, spherical, 26-43μm in diameter.