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The poinsettia ( or )〔 entry "poinsettia"〕〔(【引用サイトリンク】work=Dictionary.com )〕 (''Euphorbia pulcherrima'') is a culturally and commercially important plant species of the diverse spurge family that is 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 common English name from Joel Roberts Poinsett,〔 the first United States Minister to Mexico,〔(Mexico )〕 who introduced the plant into the United States in 1825. ==Description== ''Euphorbia pulcherrima'' is a shrub or small tree, typically reaching a height of . The plant bears dark green dentate leaves that measure 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.〔(【引用サイトリンク】title=How To Make Poinsettia Turn Red: Make A Poinsettia Rebloom )〕 The flowers of the poinsettia are unassuming and do not attract pollinators. They are grouped within small yellow structures found in the center of each leaf bunch, and are called cyathia. The poinsettia 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.〔Trejo, L., M. E. Olson, P. Feria, K. M. Olsen, L. E. Eguiarte, B. Arroyo y J. A. Gruhn. 2012. "Poinsettia’s wild ancestor in the Mexican dry tropics: historical, genetic, and environmental evidence." American Journal of Botany 99: 1146–1157.〕 Reports of ''E. pulcherrima'' growing in the wild in Nicaragua and Costa Rica have yet to be confirmed by botanists.〔Joel Roberts Poinsett. Columbia Electronic Encyclopedia, 6th Edition (online ). November 2011;:1. Available from: Academic Search Complete, Ipswich, MA. Accessed November 8, 2012〕 There are over 100 cultivated varieties of poinsettia. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Poinsettia」の詳細全文を読む スポンサード リンク
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