Euphorbia pulcherrima, commonly known as poinsettia, christmas star, winter rose or noche buena, is a species of flowering plant indigenous to Mexico and Central America. The name "poinsettia" is after Joel Roberts Poinsett, the first United States Minister to Mexico,who introduced the plant into the US in 1825.
The species is native to Mexico. It is found in the wild in deciduous tropical forest at moderate elevations from southern Sinaloa down the entire Pacific coast of Mexico to Chiapas and Guatemala. It is also found in the interior in the hot, seasonally dry forests of Guerrero, Oaxaca, and Chiapas. Reports of E. pulcherrima growing in the wild in Nicaragua and Costa Rica have yet to be confirmed by botanists. There are over 100 cultivated varieties of poinsettia available.
The plant's association with Christmas began in 16th century Mexico,
where legend tells of a young girl who was too poor to provide a gift
for the celebration of Jesus' birthday. The tale goes that the child was inspired by an angel to gather weeds from the roadside and place them in front of the church
altar. Crimson "blossoms" sprouted from the weeds and became beautiful
poinsettias. From the 17th century, Franciscan friars in Mexico included the plants in their Christmas celebrations. The star-shaped leaf pattern is said to symbolize the Star of Bethlehem, and the red color represents the blood sacrifice through the crucifixion of Jesus.
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 bracts—which
are most often flaming red but can be orange, pale green, cream, pink,
white or marbled—are actually leaves; because the flowers are unassuming
and do not attract pollinators, brightly coloured leaves developed (aka
bracts). The colors come from photoperiodism,
meaning that they require darkness for 12 hours at a time for at least 5
days in a row to change color. At the same time, the plants need a lot
of light during the day for the brightest color.
From Wikipedia
http://en.wikipedia.org/wiki/Euphorbia_pulcherrima
