In the simplest terms, Tree Peonies are shrubby plants which originated in China. Although very different in plant form from the herbaceous Peonies, Tree Peonies are also members of the great genus Paeonia. They are deciduous shrubs, which grow fast each spring, then flower dramatically in September, through till November, depending upon the variety concerned.
The flower illustrated is a Japanese variety of Tree Peony, called "Shimane Hakugan". It is a stunning pure white flower, with a golden ring of stamens around the central wine-red sheath, which at this early stage of the flower's development, encloses the female organs of the flower, the carpels.
There is a vast history of cultivating these plants in China, going back at least until the Sung Dynasty (960 - 1279). This tradition continues to the present day, especially in large public parks, dedicated Peony Gardens, in certain areas of the country, notably in Heze, and Luoyang.
Tree Peonies were introduced to Japan by Buddhist monks from Korea and China, some time in the 11th Century, apparently (some "authorities" state that it was as early as the 6th Century, but that does not fit with the earliest known dates of cultivation in China). Flowers with simpler forms, such as the one illustrated, have been favoured in Japan, in preference to the heavier flowered forms traditionally grown in China.
Tree Peonies were unknown in Western culture until the late 18th Century. The first Tree Peony in England was introduced there by Sir Joseph Banks. Banks had seen botanical reports of the fabled "Moutan" (the Tree Peony) in China, and commissioned trade agents in Canton to seek out these plants, and the first Tree Peony in England was planted in the Kew Gardens in 1787.
After the opening up of trade with China, and then Japan, there was a craze in Europe for "all things Oriental". This included Peonies. The herbaceous "Lactiflora Peonies" were the most popular, mostly for ease of growing, and propagation. However, the craze included Tree Peonies. Tree Peonies, in particular, became popular images on fabrics and upholtery. In ceramic ware, the leading British ceramicists popularised designs which were derivative copies of traditional Chinese and Japanese designs. This popularity faded some time after the 1920s. Throughout this period of time, the best known Tree Peonies in Europe were the heavy-flowered Chinese varieties.
Several European Peony growers hybridised those plants with yellow and red flowered species of Tree Peonies (from Tibet and remote rural areas of China), thus introducing new colour ranges of yellow, and bronze-red amongst large-flowered Tree Peonies. Professor Henry was the first to introduce his "Lutea hybrids" in 1907, followed by Victor Lemoine in 1910. Subsequently, his son Emile Lemoine introduced a number of famous hybrids through until 1949.
In America, in the early 20th Century, there were some private estates which held huge collections of Japanese Tree Peonies. These plants, mostly of the more elegant single and semi-double forms which were preferred by the Japanese, were destined to become part of the next phase in the story of Tree Peonies, as they were to play their part in the development of the modern Hybrid Tree Peony.