Tridax  Tridax is a genus of flowering plants in the daisy family. "Tridax" is native primarily to the tropical regions of North and South America. "Tridax procumbens" has become naturalized in the southern United States and is considered a noxious weed in some places. "Tridax procumbens" The pollen grains of Tridax "Tridax procumbens"   see "Calea Layia Sabazia"