Editing Poinsettia (section)

== Description ==
[[File:Euphorbia_pulcherrima_(Barlovento)_04.jpg|thumb|A full-grown specimen of ''E. pulcherrima''|alt=A cluster of red and green leaves leans toward the viewer on long, bent branches bursting out from a main plant on the base of a rock wall.]]
[[File:Euphorbia pulcherrima Blanco1.167-cropped.jpg|thumb|alt=A colored illustration shows the tip of a wild poinsettia branch. The leaves are less densely clustered. Leaves are long and ovate; most are red but one is green, and one is red at the base and green at the tip.|Scientific illustration of ''E. pulcherrima'', ca. 1880]]
''Euphorbia pulcherrima'' is a shrub or small tree, typically reaching a height of {{convert|0.6|-|4|m|ft|0}}. The plant bears dark green [[Crenate|dentate]] leaves that measure {{convert|6|-|16|cm|in}} in length. The colored [[bracts]]&mdash;which are normally flaming red, with cultivars being orange, pale green, cream, pink, white, or marbled&mdash;are often mistaken for flower [[petal]]s because of their groupings and colors, but are actually leaves.<ref name="Poinsettia Facts"/><ref name="UoVE"/> The colors of the bracts are created through [[photoperiodism]], meaning that they require darkness (at least fourteen hours at a time for 6&ndash;8 weeks in a row) to change color. The plants also require abundant light during the day for the brightest color.<ref>{{cite web|url=https://extension.sdstate.edu/are-you-photoperiodic-poinsettias-are|title=Are you Photoperiodic? Poinsettias Are| date=4 December 2018| first=David| last=Graper| website=SDSU Extension| publisher=South Dakota State University}}</ref> [[Semi-evergreen]], they generally lose most of their leaves during winter.<ref>[https://www.ukhouseplants.com/plants/poinsettia Why Do Poinsettias Die After Christmas?] POINSETTIA. ukhouseplants. Retrieved 15 August, 2023.</ref>

The flowers of the poinsettia are unassuming. They are grouped within the [[cyathium|cyathia]] (small yellow structures found in the center of each leaf bunch, or false flowers).<ref name="Poinsettia Facts">{{cite web | url=http://urbanext.illinois.edu/poinsettia/facts.cfm | title= Poinsettia Facts| publisher=[[University of Illinois]] Extension | work=The Poinsettia Pages | access-date=January 30, 2017 |author1=Seltzer, Erica D. |author2=Spinner, MaryAnne}}</ref> Nothing is known about [[pollination]] in wild poinsettias, though [[wasp]]s are noted to occasionally visit the cyathia.<ref name="Trejo"/> All flowers in the Euphorbiaceae are [[Unisexual flowers|unisexual]] (either male or female only), and they are often very small in size. In ''Euphorbia'', the flowers are reduced even more and then aggregated into an [[inflorescence]] or cluster of flowers.<ref>{{Cite web|title=EUPHORBIA PBI|url=http://www.euphorbiaceae.org/pages/about_euphorbia.html|access-date=2020-12-11|website=www.euphorbiaceae.org|archive-date=March 28, 2009|archive-url=https://web.archive.org/web/20090328121630/http://www.euphorbiaceae.org/pages/about_euphorbia.html|url-status=dead}}</ref> [[Extrafloral nectaries]] in ''E. pulcherrima'' were first reported by Zimmerman in 1932.<ref>{{cite journal |date=2012-10-18 |first1=Marjorie G. |last1=Weber |first2=Kathleen H. |last2=Keeler |title=The phylogenetic distribution of extrafloral nectaries in plants |pages=1251–1261 |doi=10.1093/aob/mcs225 |journal=Annals of Botany |eissn=1095-8290 |volume=111 |issue=6|pmc=3662505 }}</ref>