First of all, people in ancient times liked to plant plane trees. It is necessary to explain something: the plane tree in ancient poetry is not the same thing as the plane tree in France today. The former belongs to the family genus of "Platanus" and its Latin name is Firmiana platanifolia (Linn. f.) Marsili. The latter belongs to the family and genus of "Platanus" and its Latin name is Platanus acerifolia. The bark of the former is green and the bark of the latter is gray. Brown or off-white; the former fruit can be fried and eaten, and tastes sweet, while the latter fruit is bitter and unpalatable. During the Tang and Song Dynasties, people all over the north and south liked to plant sycamore trees. Because sycamore trees are relatively clean and have luxuriant branches, they can be shaded under them in summer. Therefore, sycamore trees are often found in courtyards and beside wells. There are poems to prove it, "The autumn leaves of the sycamore trees in Jinjing are yellow, and the bead curtains are not curled up by the frost at night" (Wang Changling's "Five Autumn Poems of Changxin"), "The sycamores and willows blow in the golden well, and they come to drunken the home of the Fufeng hero" (Li Bai's "Song of the Fufeng hero") ), "Crickets chirp in the bridal chamber, and parasol trees fall into the golden well" (Zhang Hu's "Two Poems on Wall Flowers"). Unlike today, in order to achieve quick "political achievements", government officials plant poplars everywhere, which the ancients liked to plant in cemeteries - just because poplars grow quickly. Secondly, in ancient times, there was a saying that "Wu" is a male tree and "Tong" is a female tree. Therefore, the phoenix tree can be used as a metaphor for the love between men and women. For example, Meng Jiao's poem "Lienvcao" contains the sentence "Wutong trees treat each other as they grow old, and mandarin ducks will die together". There is a saying in "Qifa" written by Han Meicheng that "the dragon's tree... its roots are half dead and half alive". Later generations also used the half-dead phoenix tree as a metaphor for widowhood. For example, Bai Juyi's poem "Mourning for Xuetai" contains the sentence "The half-dead Wutong is old and sick, and the thought of heavy springs hurts the mind." Again, it is related to some characteristics of the sycamore tree. The sycamore tree is a broad-leaved plant. When raindrops hit the leaves, the sound is easily audible. Yao He's "Hangzhou Official Residences": "The moss is dusty, and the sycamores are making the sound of rain." This is a bit like a lotus leaf, and Li Shangyin has a poem that "leaves the withered lotus to listen to the sound of rain." The sycamore tree is a deciduous plant. When autumn comes, the leaves fall off one after another, which can easily give people a feeling of desolation and desolation. Bai Juyi's "Song of Everlasting Regret": "The peach and plum blossoms bloom in the spring breeze at night, and the sycamore leaves fall in the autumn rain." The sycamore tree trunk is an excellent material for making harp and harp. The sound of rain and harp can communicate with each other, making people cry and express sadness. Yan Shu's "Wu Tong": "It can be used as a harp, the harmony of spring and autumn." The sycamore tree is an arbor and has sweet-tasting fruits, so it is considered a tree of high quality and is the habitat and food source of the legendary Phoenix. (Wu Tong Zi). In "Zhuangzi", there is already a saying that "the bird's bird originates from the South China Sea and flies over the North Sea, and it is not stopped by the parasol trees" ("Autumn Water Chapter"). In Tang poetry, there are many lines about the phoenix perched on the sycamore tree. For example: "The scales are playing in the waves, the phoenixes are perching on the phoenix trees" (Gao Shi's "Rewarding the Secretary and the Princes"), "The fragrant rice pecks at the remaining parrot grains, and the green parasols are perched on the old phoenix branches" (Du Fu's "Autumn Xing Eight") "First Song"), "Golden ears of willows, jasper branches of sycamore trees" (Linghu Chu's "Two Songs of Farewell and Separation").