Here"s the red poinsettia, one of the plants synonymous with the holiday season across North America. With its striking star-shaped leaves, the poinsettia has become a symbol of Christmas cheer, brightening homes and public spaces during winter. National Poinsettia Day in the United States celebrates the legacy of Joel Roberts Poinsett, the first US ambassador to Mexico, who introduced these vibrant plants to America in the 1820s. He discovered them while exploring the Taxco region in Guerrero and, so taken by their beauty, sent clippings back to his home in Charleston, South Carolina.