China's "king of flowers" could soon become an orphan. The tree peony may be the favourite flower of the first lady but nearly all of its genetic parents in the wild are close to extinction because of inadequate protection, according to a new study by mainland scientists. The flowering plant is native to China and blooms in rich, vibrant colours. It was the national flower before being replaced in 1929 by the plum tree. First lady Peng Liyuan is one of its well-known admirers. Born in Heze , a city in Shandong province dubbed the "town of tree peonies", Peng frequently includes the flower in her formal dress or gives it as a gift to foreign guests. Though the plant has been cultivated in China for more than 1,000 years, its origin remained a puzzle until recently. There was much speculation on how the flower acquired its impressive colours. One theory was that it was the result of crossbreeding of numerous wild species, but botanists long lacked the hard evidence needed to make a conclusion. The mystery has now been solved by a team from the Institute of Botany at the Chinese Academy of Sciences. The researchers found that the tree peony was the hybrid child of five wild species in central China, and that nearly all of these parental species were critically endangered. "Without immediate protection, they will all go extinct quickly," said Hong Deyuan, a professor of the State Key Laboratory of Systematic and Evolutionary Botany and the leading scientist of the study. The researchers' findings were published in the academic journal Proceedings of the Royal Society B early last month. Wild tree peonies are now very rare, but scientists needed as many samples as possible for genetic analysis to recreate the road map of the plant's evolution. The new findings were the result of three decades of work, Hong said. Since 1985, his team had been collecting peony samples in China and around the world. They found a total of nine wild species with locations spanning from the Tibetan Plateau to the lower reaches of the Yellow River. They are all native to China but only five in the heartland of Chinese culture such as Henan and Shaanxi were involved in the crossbreeding process. But now very few of them can be found in the wild. The bark of the tree peony was an important ingredient for Chinese medicine, and most wild varieties have disappeared because of the lack of protection. "Most strikingly, P. cathayana , the maternal parent for the majority of the traditional cultivars, had only one single individual found in mountains south of Luoyang ," they wrote in the paper. " Paeonia ostii also has only one individual found on a cliff in central Anhui province . It is clear that the wild populations of the species have nearly been eradicated." Some local governments were unwilling to spend money to protect these rare species, because such projects could not produce immediate economic returns.