Aeolanthus biformifolius (Labiatae) from Shaba Province, Zaire, has been shown to be a hyperaccumulator of copper. The copper content of the total plant during the rest period after the rainy season was 1.3 percent (dry weight basis) and is easily the highest copper concentration ever found in living material. This species should be classified as a copper flower because of its exclusive occurrence over mineralized ground.