What examples of distant grafting of plum blossoms were recorded in ancient China?

There are many examples of distant grafting of plum blossom recorded in ancient China. There are two ways to pick plums in the Tree Planting Book: "Picking plums on mulberry leaves is not sour ... picking plums on neem trees produces plum blossoms." "Knowing the Sound and Knowing the Book" also introduces a method of picking plums: "There is a method of picking white plum trees with wintersweet, and its fragrance and color are like petals, so it is wintersweet." Birds of a feather flock together, and it is recorded in the book that "Holly trees gather plums and open ink plums". In addition, "Compendium of Materia Medica" wrote: "According to legend, Zhenwu Zhemei branch is inserted in Shulang ... This tree is still in the north of Wulong Palace, and the Langmu is apricot-shaped." The author has been trying these methods for many years, but they are all unsuccessful. I don't know if it was imagined by the ancients, or if there is such a method, which needs further confirmation.