While Poinsettia plants are not actually poisonous, I was recently asked about this. As a concerned parent of two young children, I decided to do some research about poisonous plants, and learned that the toddler in my life is more harmful to my Poinsettia houseplant than the plant is to him.
Upon visiting the site and searching for 'humans,' a list of 22 plants was returned. This site has good color pictures of plants, animals affected, and geographic locations of these plants. Of course, there are many plants we are not likely to plant in our landscapes (like leafy spurge, water hemlock, death camas, or buckeyes). Yet, there are some plants that may find their way into our landscapes or potted plants (like Oleander, Autumn crocus, Glory lily, Rhododendron, Delphinium and Daffodils) that are toxic. Easter lilies are especially toxic to house cats.
I also visited the Cornell University website for toxic plants, http://www.ansci.cornell.edu/plants/index.html and did a search for plants poisonous to humans. About 55 plants were returned in this search (including several mushroom species). Included in this list is the Poinsettia, which was surprising. The Society of American Florists has given a 'Clean Bill of Health' to the Poinsettia plant. It is, however, wise to keep Poinsettias and other plants out of the reach of children and household pets that show a desire to chew or eat plants. The white latex sap in the leaves and stems is mildly irritating to the mucous membranes of the mouth, and for some animals it will induce excessive salivation and vomiting if plant parts are swallowed. The wide variety of hybrid poinsettias available today have very little toxicity compared to the parent species. Other Euphorbia’s, include the various spurges, have been shown to be hazardous to humans when handled or consumed.
I also researched the incidence of plant poisonings for this article and was surprised at some of the findings. According to the American Association of Poison Control Centers, there were 64,236 (2.7 %) cases involving plants. In pediatrics (age 5 or less), the percentage is higher (3.7%). Of the plant calls received by poison control centers involved in this report, the Poinsettia was number 2 on the list. For more information, visit their website at http://www.aapcc.org. Should you suspect poisoning, call 1-800-222-1222. If it is an emergency, of course, dial 911.
Kurt Jones is the CSU Chaffee County Extension Director