Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae or Leguminosae. Its name is formed from the generic name Caesalpinia. It is known also as the peacock flower family. The Caesalpinioideae are mainly trees distributed in the moist tropics, but include such temperate species as the honeylocust (Gleditsia triacanthos), Kentucky coffeetree (Gymnocladus dioicus), and redbud (Cercis canadensis). Their flowers are zygomorphic, but are very variable. Nodulation is rare in this subfamily, and where it does occur, nodules have a primitive structure.