Poinsettias originally came from Mexico, where they grow as a large shrub. The poinsettia plant is named after Joel Poinsett, a botanist and physician who brought poinsettias to the United States in 1828.
The Aztecs called the poinsettia plant "Cuitlaxochitl," which means "flower that grows in soil." In Mexico, it is called "la flor de Nochebuena" ("the Christmas Eve flower"), and in parts of South America, it is known as "la corona de los Andes" ("the crown of the Andes").
It is best to keep poinsettias away from pets because the leaves, if ingested, can cause diarrhea and vomiting. They are not extremely poisonous, however. A 50-pound child would have to ingest 500 leaves for any long-term effect.