Пуансеттия: История, Описание и Распространенные Мифы

Species of flowering plant in the spurge family Euphorbiaceae

The poinsettia (/p//ɔɪ//n/'/s//ɛ//t//(//i//)//ə/; Euphorbia pulcherrima) is a commercially important flowering plant species of the diverse spurge family Euphorbiaceae. Indigenous to Mexico and Central America, the poinsettia was first described by Europeans in 1834. 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 is credited with introducing the plant to the US in the 1820s. Poinsettias are shrubs or small trees, with heights of Though often stated to be highly toxic, the poinsettia is not dangerous Klotzsch credited Carl Ludwig Willdenow with the species name "pulcherrima", and the authority is given as Willd. ex Klotzsch. The holotype had been collected in Mexico during an 1803–1804 expedition by Alexander von Humboldt and Aimé Bonpland. It was known by the common name "poinsettia" as early as 1836, Prior to poinsettia, it was known as "Mexican flame flower" or "painted leaf". Semi evergreen, they generally lose most of their leaves during winter. The flowers of the poinsettia are unassuming. They are grouped within the cyathia (small yellow structures found in the center of each leaf bunch, or false flowers). Nothing is known about pollination in wild poinsettias, though wasps are noted to occasionally visit the cyathia.

Pulcherrol and pulcherryl acetate are among the components of its latex. Triterpenes are found in aerial parts of the plant, including its latex and leaves. One such triterpenoid skeleton is being investigated for its anti Alzheimer's disease bioactivity.

Poinsettias are popularly, though incorrectly, said to be toxic to humans and other animals. In 1944, the plant was included in H. R. Arnold's book Poisonous Plants of Hawaii on this premise. Though Arnold later admitted that the story was hearsay and that poinsettias were not proven to be poisonous, the plant was thus thought deadly. In 1970 the US Food and Drug Administration published a newsletter stating erroneously that "one poinsettia leaf can kill a child", and in 1980 they were prohibited from nursing homes in a county in North Carolina due to this supposed toxicity. An attempt to determine a poisonous dose of poinsettia to rats failed, even after reaching experimental doses equivalent to consuming 500 leaves, or nearly of sap. Contact with any part of the plant by children or pets often has no effect, though it may cause nausea, diarrhea, or vomiting if swallowed. External exposure to the plant may result in a skin rash for some. A survey of more than 20,000 calls to the American Association of Poison Control Centers from 1985–1992 related to poinsettia exposure showed no fatalities. In 92.4% of calls, there was no effect from exposure, and in 3.4% of calls there were minor effects, defined as "minimally bothersome". It can induce asthma and allergic rhinitis in certain groups of people.

The Aztecs were the first to cultivate poinsettias. Cultivation in the US began when diplomat Joel Roberts Poinsett sent some of the plants back to his greenhouses in South Carolina in the 1820s. Specific details about its spread from there are largely unverifiable, but it was exhibited at the Pennsylvania Horticultural Society's 1829 Philadelphia Flower Show by Colonel Robert Carr. Carr described it as "a new Euphorbia with bright scarlet bracts or floral leaves, presented to the Bartram Collection by Mr. Poinsett, United States Minister of Mexico." Each year in the US, approximately 70 million poinsettias are sold in a period of six weeks, at a value of US$250 million. In Puerto Rico, where poinsettias are grown extensively in greenhouses, the industry is valued at $5 million annually. There are over 100 cultivated varieties of poinsettia that have been patented in the US. 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 in the growth of axillary buds is credited to Ing Ming Lee of the USDA Agricultural Research Service.

Albert Ecke emigrated from Germany to Los Angeles in 1900, opening a dairy and orchard in the Eagle Rock area. He became intrigued by the plant and sold them from street stands. His son, Paul Ecke, developed the grafting technique, but it was the third generation of Eckes, Paul Ecke Jr., who was responsible for advancing the association between the plant and Christmas. Until the 1990s, the Ecke family, who had moved their operation to Encinitas, California, in 1923, had a virtual monopoly on poinsettias owing to a technique that made their plants much more attractive. They produced a fuller, more compact plant by grafting two varieties of poinsettia together. A poinsettia left to grow on its own will naturally take an open, somewhat weedy look. The Eckes' technique made it possible to get every seedling to branch, resulting in a bushier plant. In the late 1980s, university researcher John Dole discovered the grafting method (grafting rarer densely branched cultivars onto more common sparsely branched cultivars) previously known only to the Eckes and published it. This allowed competitors to flourish, particularly those using low cost labor in Latin America. The Ecke family's business, now led by Paul Ecke III, decided to stop producing plants in the US, but as of 2008, they still served about 70 percent of the domestic market and 50 percent of the worldwide market.

Poinsettias are susceptible to several diseases, mostly fungal, but also bacterial and parasitic. Conditions that promote poinsettia propagation also favor certain diseases. Fungal diseases affecting greenhouse poinsettia operations include Pythium root rot, Rhizoctonia root and stem rot, black root rot, scab, powdery mildew, and Botrytis blight. Bacterial diseases include bacterial soft rot and bacterial canker, while a viral disease is Poinsettia mosaic virus. Infection by poinsettia branch inducing phytoplasma is actually desirable, as it keeps the plants shorter with more flowers. It is the first known phytoplasma that has economically advantageous effects.