This undated file photo shows Chinese cherry apple flowers in the Palace Museum in Beijing, capital of China. (Xinhua/Palace Museum)

This undated file photo shows wintersweet flowers in the Palace Museum in Beijing, capital of China. (Xinhua/Palace Museum)

This undated file photo shows lotus flowers in the Palace Museum in Beijing, capital of China. (Xinhua/Palace Museum)

This undated file photo shows blossoming flowers in the Palace Museum in Beijing, capital of China. (Xinhua/Palace Museum)

This undated file photo shows peony flowers in the Palace Museum in Beijing, capital of China. (Xinhua/Palace Museum)

This undated file photo shows blossoming flowers in the Palace Museum in Beijing, capital of China. (Xinhua/Palace Museum)

Photo taken on Sept. 27, 2016 shows tourists viewing chrysanthemum flowers in the Palace Museum in Beijing, capital of China. (Xinhua/Palace Museum)