Poinsettia

Appearance

''Euphorbia pulcherrima'' is a shrub or small tree, typically reaching a height of 0.6 to 4 m . The plant bears dark green dentate leaves that measure 7 to 16 cm 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 to change color. At the same time, the plants require abundant light during the day for the brightest color.

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. Reports of ''E. pulcherrima'' growing in the wild in Nicaragua and Costa Rica have yet to be confirmed by botanists.

There are over 100 cultivated varieties of poinsettia.

Defense

In the United States and perhaps elsewhere, there is a common misconception that the poinsettia is highly toxic. This misconception was spread by a 1919 urban legend of a two-year-old child dying after consuming a poinsettia leaf.

While the sap and latex of many plants of the spurge genus are indeed toxic, the poinsettia's toxicity is relatively mild. Its latex can cause an allergic reaction in sensitive individuals. It is also mildly irritating to the skin or stomach and may sometimes cause diarrhea and vomiting if eaten. Sap introduced into the human eye may cause temporary blindness. An ''American Journal of Emergency Medicine'' study of 22,793 cases reported to the American Association of Poison Control Centers showed no fatalities, and furthermore that a strong majority of poinsettia exposures are accidental, involve children, and usually do not result in any type of medical treatment. POISINDEX, a major source for poison control centers, says it would take 500 bracts for a 50-pound child to eat an amount found to be toxic in experiments. An Ohio State University study showed no problems even with extremely large doses.