Poinsettias are one of the most popular Christmas plants, and their association with the holiday dates back to the 16th century. In Mexico, they are known as "Flores de Noche Buena," which means "flowers of the Holy Night." Legend has it that a young girl was too poor to buy gifts for the Nativity, so she gathered weeds from the side of the road and put them in front of the church. Suddenly, the weeds bloomed into beautiful red flowers, and they became a symbol of the true meaning of Christmas.