A pamphlet called "Take Care With Plants" from the regional poison center at UC Irvine Medical Center lists plants that are toxic or possibly toxic. The pamphlet is available by writing to the University of California Irvine Medical Center, 101 The City Drive, Route 78, Orange 92668.
Among the plants listed are the geranium (California and Pelargonium species), chrysanthemum and pansy (tricolor variety). According to the pamphlet, California geraniums may be toxic, damaging stomach, heart, kidneys or other organs while the sap of the Pelargonium may produce a skin rash. Certain chrysanthemum species may have toxic and dermatological effects, and tricolor pansies may cause dermatitis.
This list contradicts "AMA Handbook of Poisonous and Injurious Plants" (Chicago Review Press) and other lists, in which those plants mentioned above are not listed among the toxic varieties, according to David Lofgren, plant specialist at the Los Angeles County Arboretum. "Many lists add a large range of plants to widen the margin of assured public safety, and not necessarily because they are actually toxic," said Lofgren. Many plants, Lofgren added, are toxic when consumed in large amounts, whereas others are toxic until boiled--tapioca, for example.
According to John Bleck, staff research associate, horticulture department, UC Santa Barbara, many lists may refer to entire plants, not necessarily the flowers alone. "Many plant species may include varieties which on one end of the scale are perfectly safe to eat, while on the other end, include plants which may be toxic," said Bleck.