Most plants contain chemicals that are in some way harmful to humans and their pets, with symptoms ranging from mild nausea and dizziness to death. The best rule-of-thumb for you and your children is not to eat or chew any parts or any plant species unless you are absolutely certain that it is harmless. In case of emergency, call the Poison Control Center.
Mushrooms are not included in this list since they are not plants. Unless you are an expert, do not eat mushrooms. Many are extremely dangerous and different people react differently to various forms. If you want to learn more about them, LNC offers courses dealing with their identification and food value.
ALL PARTS POISONOUS: dieffenbachia, caladium, elephant ear, philodendron, autumn crocus, aconite, monkshood, foxglove, belladonna, laurels, rhododendrons, other azaleas, oaks, oleander, Jack-in-the-pulpit, skunk cabbage, jimsonweed, nightshades, horse nettles, water hemlock, poison hemlock, buttercups, elderberry (except ripe fruits and flowers), pokeweed (except young leaves), anemone, California poppy, amaryllis, blue bonnets, clematis, daffodil, delphinium, horsetail, hydrangea, jasmine, lillies, mimosa, mistletoe, night-blooming cereus, periwinkle, raintree, strawberry bush, yucca, ligustrum, Jerusalem cherry, moon flower.
BULBS, ROOTS, RHIZOMES, ETC.: hyacinth, star of Bethlehem, iris, bleeding heart, mayapple, cyclamen, four o’clocks, spider lilly, Spanish bayonet, violets, tulips, death camas, pansies.
LEAVES AND/OR BARK: iris, Dutchman’s breeches, larkspur, lily-of-the valley, nicotiana, potato, Carolina and yellow jessamine, privet,daphne, English ivy, oleander, yew, black locust, buckeye, horse chestnut, wild black cherry, chokecherry, baneberry, mayapple, poinsettia, rhubarb, bleeding hearts, allamanda, boxwood, primrose, tomato, pomegranate, sweet pea, century plant, cherry laurel, lobelia, wandering Jew, Virginia creeper.
FRUITS: moonseed, mayapple (unripe), privet, poppies, mock orange, chinaberry, baneberry, holly, yaupon, lily-of-the-valley, daphne, English ivy, red sage, lantana, jasmine, yew, lobelia, sago palm, Chinese tallow.
SEEDS: camellia, loquat, tung tree, castor bean, rosary pea, larkspur, apples, black locust, buckeye, horse chestnut, jatropha, cherries, yew, wisteria (and pods), golden chain, cherry laurel, Chinaberry, morning glory.
PLANTS COMMONLY CAUSING DERMATITIS: poison ivy (= poison oak), poison sumac, trumpet creeper, stinging nettle, eyebane, wild parsnip, Hercules club, Jack-in-the-pulpit,asparagus, marijuana, catalpa, virgins-bower, autumn crocus, poison hemlock, lily-of-the-valley, lady slippers, daphne, jimsonweed, wild carrot, larkspur, daisy fleabane, spurges, yellow jessamine, maidenhair tree, English ivy, spurge nettle, Juniper, wood nettle, lobelia, osage orange, oleander, mayapple, smartweed, some buttercups, rhubarb, curly dock.
KINGSBURY, J. M. 1964. Poisonous plants of the United States and Canada. Prentice-Hall, Inc., Englewood Cliffs, NJ.
KINGSBURY, J. M. 1965. Deadly harvest: a guide to common poisonous plants. Holt, Reinhardt, and Winston, New York.
MUENSCHER, W. C. 1975 (rev.). Poisonous plants of the United States. Macmillan Books, New York. 277 pp.