The poinsettia, (Euphorbia pulcherrima) is a plant species indigenous to Mexico and Central America. It is particularly well known for its red and green foliage and is widely used in Christmas floral displays. It derives its name from Joel Roberts Poinsett, the first United States Minister to Mexico, who introduced the plant into the United States in 1825. Euphorbia pulcherrima is a shrub or small tree, typically reaching a height of 0.6 to 4 m (2 to 16 ft). The plant bears dark green dentate leaves that measure 7 to 16 cm (3 to 6 inches) in length. The colored bractswhich are most often flaming red but can be orange, pale green, cream, pink, white or marbledare often mistaken for flower petals because of their groupings and colors, but are actually leaves. The colors of the bracts are created through photoperiodism, meaning that they require darkness (12 hours at a time for at least 5 days in a row) to change color.
Contributions by Xanzzibar, ClueBot, and JoJan.