According to Google: The shape of the poinsettia flower and leaves are sometimes thought as a symbol of the Star of Bethlehem which led the Wise Men to Jesus. The red colored leaves symbolize the blood of Christ. The white leaves represent his purity.
They’ve become a holiday tradition world-wide, and are widely grown indoors over Christmas for their brightly colored bracts.
In fact, it’s quite possible that the plant you have in your home right now was grown right here in the NW. The Van Wingerden family have greenhouses in Blaine. The family supplies every Safeway store in Washington and distributes from Alaska to California.
History of the POINSETTIA.