Fast Five Quiz: Toxic Plants

Richard H. Sinert, DO


November 23, 2021

According to the 2019 Annual Report of the American Association of Poison Control Centers' National Poison Data System, 5803 exposures were documented for oxalate plant poisonings.

Nonsoluble calcium oxalate crystals are found in plant stems, roots, and leaves. The stalk of the dieffenbachia plant produces the most severe reactions. When these needlelike crystals come in contact with the lips, tongue, oral mucosa, conjunctiva, or skin, they produce pain and edema. Edema is primarily due to direct trauma from the needlelike crystals and, to a lesser extent, by other plant toxins (eg, bradykinins, enzymes).

Plants that contain oxalates include:

  • Anthurium (Anthurium species)

  • Arum, araceae (Arisaema species)

  • Caladium (Caladium bicolor)

  • Calla lily (Zantedeschia species)

  • Chinese evergreen (Aglaonema species)

  • Dieffenbachia (Dieffenbachia species)

  • Jack-in-the-pulpit (Arisaema triphyllum)

  • Monstera, ceriman (Monstera deliciosa)

  • Nephthytis (Syngonium podophyllum)

  • Philodendron (Philodendron species) (See image below.)

  • Pothos or hunter's robe (Epipremnum aureum)

  • Skunk cabbage (Symplocarpus foetidus)

Figure 1. Philodendron (Philodendron gloriosum).

African violet, baby's tears, and prayer plant are considered to be nontoxic plants.

Learn more about plant poisoning from oxalates.


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