Koelreuteria elegans, more commonly known as flamegold or Taiwanese rain tree, is a deciduous tree to 15-20 metres native to Taiwan. It is widely grown throughout the tropics and sub-tropical parts of the world as a street tree. It flowers in early to mid-summer. Flowers are small, to 20 mm in length, and occur in branched clusters at the stem tips. They are butter-yellow with five petals that vary in length until opening. Each flower contains seven to eight pale yellow stamens with hairy white filaments.