About

The poinsettia (; 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; however, there have been recent efforts to rename the flower to its Nahuatl name, "cuetlaxōchitl", due to Poinsett's involvement in slavery and the Trail of Tears. Poinsettias are shrubs or small trees, with heights of 0.6 to 4 m (2.0 to 13.1 ft). Though often stated to be highly toxic, the poinsettia is not dangerous to pets or children.

How to grow it

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."

The poinsettia is the world's most economically important potted plant. 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.

Safety

Poinsettias are popularly, though incorrectly, said to be toxic to humans and other animals. This misconception was spread by a 1919 urban legend of a two-year-old child dying after consuming a poinsettia leaf. 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 1 kg (2.2 lb) 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.

Where it grows

The poinsettia occurs in North and Central America, from Mexico to southern Guatemala. Its range is about 2,000 km (1,200 mi) long, encompassing mid-elevation tropical dry forests. Most wild populations are on Pacific-facing slopes in steep canyons. Populations were once found in rolling hill areas, though many have gone extinct. It has been hypothesized that the inaccessibility of the canyons may protect the wild populations from human disturbance. There is a somewhat anomalous population of wild poinsettias in the northern part of the Mexican state of Guerrero and Oaxaca, which is much further inland in the hot and seasonally dry forests than the rest of the species' range. Genetic analyses showed that the wild populations in northern Guerrero are the likely ancestors of most cultivated poinsettias.

Other Euphorbia plants

Abd Al Kuri Euphorbia · Desert Candle · Greek Spiny Spurge · Euphorbia actinoclada · Miniature Saguaro · Pincushion Euphorbia · Euphorbia alcicornis · Euphorbia alfredii · Euphorbia ambarivatoensis · Euphorbia ambovombensis · African candelabra · Euphorbia ampliphylla