The Flying dragon (Poncirus trifoliata cv. Frying Dragon) belongs to Rutaceae (the Citrus family). It is a small deciduous tree that is a cutivar of "Hardy orange". The tree is less vigorous than the Hardy orange, the height of the tree is 2 to 4 meters, and the branches and thorns are contorted. The leaves are alternated, trifoliate, yellowish-green in spring, turn glossy dark green in summer and fade to yellow in fall. The slightly fragrant, white, 4-7 petaled flowers appear in spring. The fruits are edible, but are very acidic and seedy. Recently, it is used as a rootstock when cultivating citrus fruits in Japan and the United States.