In 825-827AD Li Zhengfeng wrote in an ode to peonies,
"their national colours in the morning show the heart's content during carousal, while their heavenly fragrance at night dyes dresses."
This is the origin of the well-known expression "National Beauty and Heavenly Fragrance".
extract from the book :
Wang Lianying 1998, Chinese Tree Peony - The Peony Association Of China - 213 pages · 400 color photos · english edition of Pictorial Record of Chinese Tree Peony Varieties