Known as the royal flower associated with the image of the Nguyen dynasty in Hue, the cornflower every year blooms in late March and early April, creating beautiful images for visitors to visit. In ancient times, the sycamore tree was a precious tree only grown in the Imperial Citadel and the tombs of the Nguyen Dynasty kings. Maize tree was also allowed by King Minh Mang to carve the image on Nhon Dinh in Dai Noi. Cornflower color is characterized by a gentle pastel pink color. When flowering, the corn leaves all the leaves and then displays small, dense inflorescences on the branches, and the flowers are light purple. Seen from above, the cornflower tree blooms with beautiful flower beds on the ancient tile floor of the imperial city of Hue. The cornfield stems rise straight in the middle of the blue sky, attracting the attention of residents and visitors. Hue Citadel is a rare place in Vietnam that has special cornflowers with stunning flower colors. According to the book Dai Nam Thong Chi, there were two corn field trees brought from Guangdong (China), King Minh Mang planted on both sides of the corner of Can Chanh (Dai Noi). Then, because he was in love with this beautiful flower, the king sent someone who knew about plants to find a native tree. In the mountainous area of ​​Vietnam at that time, there were many species of plants with the same morphology as corn, so it took people who were really good at plants to choose native maize to plant in the Imperial City. At this time, visitors to Hue citadel will be able to see the blooming corn plants with their own eyes. Considered as one of the rare “herbaceous flowers” especially rare, the sycamore tree is being propagated by Hue Monuments Conservation Center for conservation.