Yes, today, December 12, is National Poinsettia Day! This plant (Euphorbia pulcherrima), a native of Mexico, was first brought to the United States by Joel Roberts Poinsett, U.S. Ambassador to Mexico, 1825-1829.
It was the Ecke family in San Diego, starting with German immigrant Albert in 1900, that brought the plant to prominence. Albert sold them from street stands; his son Paul developed the grafting technique for propagation; and Paul Jr. promoted it as a Christmas plant. The idea caught on, and beautiful red poinsettias – and white, pink, and other varieties – are everywhere during the Christmas season.