<Tr> <Th_colspan="2"> Binomial name </Th> </Tr> <Tr> <Td_colspan="2"> Euphorbia pulcherrima Willd . ex Klotzsch </Td> </Tr> <P> The poinsettia (/ pɔɪnˈsɛtiə / or / pɔɪnˈsɛtə /) (Euphorbia pulcherrima) is a commercially important plant species of the diverse spurge family (Euphorbiaceae). The species is indigenous to Mexico . It is particularly well known for its red and green foliage and is widely used in Christmas floral displays . It derives its common English name from Joel Roberts Poinsett, the first United States Minister to Mexico, who introduced the plant to the US in 1825 . </P> <P> Euphorbia pulcherrima is a shrub or small tree, typically reaching a height of 0.6--4 metres (2--13 ft). The plant bears dark green dentate leaves that measure 7--16 centimetres (2.8--6.3 in) in length . The colored bracts--which are most often flaming red but can be orange, pale green, cream, pink, white, or marbled--are 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 five days in a row) to change color . At the same time, the plants require abundant light during the day for the brightest color . </P>

When was the poinsettia brought to the us