Euphorbia subg. Poinsettia 1858, but promoted to subgenus rank by Homer Doliver House in 1924. Recent studies have confirmed its monophyly. Its many species include: The common name "wild poinsettia" is sometimes applied to two of these species. Euphorbia subg. Poinsettia Euphorbia" subg. "Poinsettia is a subgenus deriving from the genus "Euphorbia", and is endemic to North America. <nowiki> </nowiki>It contains around 24 species, of which the best known is "E. pulcherrima", the poinsettia. This species grows wild in the mountains on the Pacific slope of Mexico, and despite many legends, no one is quite sure from which wild populations the cultivated varieties
Poinsettia by bright sunny days for around two months in autumn in order to encourage it to develop colored bracts. Any incidental light during these nights (from a nearby television set, from under a door frame, even from passing cars or street lights) hampers bract production. Commercial production of poinsettia has been done by placing them inside a greenhouse and covering the latter completely to imitate the natural biological situation. To produce extra axillary buds that are necessary for plants containing multiple flowers, a phytoplasma infection—whose symptoms include the proliferation of axillary buds—is used. The discovery of the role phytoplasmas play