The cornus worn by people in the Tang Dynasty on the Double Ninth Festival is Evodia rutaecarpa. The Evodia rutaecarpa worn by the ancients is the Evodia rutaecarpa in botany today, and it is unlikely that it is an edible cornus (Zanthoxylum bungeanum) whose branches are full of thorns and easy to prick people.
Evodia rutaecarpa refers to the rutaceae plant Evodia rutaecarpa, and eating cornus refers to another rutaecarpa plant, Zanthoxylum bungeanum, whose branches, leaves and fruits have a strong smell (whether it is fragrant or smelly varies with people's feelings), especially the fruit, which is very spicy in the mouth.
In fact, Wang Wei planted Evodia rutaecarpa in his Wangchuan manor in his later years, creating a scenic spot called "cornus Yi". There is a poet named Pei Di who often sings with Wang Wei. After visiting cornus in late autumn, he wrote this poem: "The fragrance is fragrant and fragrant, and the leaves are fragrant." Although the clouds are shining back, the forest is heavy and cold. " Since cornus here can be "fragrant" and can be mistaken for the smell of pepper and cinnamon, it can only be Evodia rutaecarpa, not Cornus officinalis. Since Evodia rutaecarpa can be planted on the northern slope of Qinling Mountains very close to Guanzhong Plain, it is entirely possible to plant Evodia rutaecarpa in Wang Wei's hometown of Shandong (now Yuncheng, Shanxi) with close latitude for Wang Wei's brothers to climb and wear.
Not only that, Wang Wei also has a poem called Cornus officinalis, which actually describes Evodia rutaecarpa. The poem says, "When Zhushi Mountain opens, the fragrance is even colder. Fortunately, with Cong Guihua, the window faces the autumn moon. " In addition to "fragrance", the phrase "Zhushi Mountain opens below" also conforms to the characteristics of Evodia rutaecarpa (the fruit will crack when it matures), but does not conform to the characteristics of Cornus officinalis (the fruit is a stone fruit and will not "open"). Therefore, the title of the poem "Cornus officinalis" should be interpreted as "cornus at the foot of the mountain", and it cannot be taken for granted that it is Cornus officinalis in this cursive script.