Radermachera sinica (China doll, Serpent tree or Emerald tree). Evergreen tree in the family Bignoniaceae, native to the subtropical mountain regions of southern China and Taiwan. It can reach heights of up to 30 m tall and a trunk diameter of 1 m. The flowers are white, trumpet-like, about 7 cm long, and resembling a large Bignonia flower in shape. Used as a houseplant and bonsai.