Poinsettias are considered by some to be most popular flower of the Christmas season. Poinsettias come in a variety of colors, including red, pink and white. Poinsettias are not considered poisonous to people or pets.
[Suwanee Democrat: The poinsettia, a holiday tradition (December 16, 2008)][Suwanee Democrat: The poinsettia, a holiday tradition (December 16, 2008)]
With its shiny green leaves and bright red berries, holly is commonly used as a decoration at Christmas.
Mistletoe is often hung in doorways; tradition holds that two people walking under the mistletoe at the same time should share a kiss. Both mistletoe and holly can be poisonous.[The Children's Hospital of Philadelphia" Berries and Seeds]
The amaryllis is another popular flower at Christmastime; it can be potted after the holidays are over.[Christian Science Monitor: The 12 days of Christmas plants - amaryllis (December 14, 2008)]