Harmful & Poisonous Plants: H-N

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H

Halogeton glomeratus (BARILLA, HALOGETON); leaves, stems; plant contains soluble oxalates.

Haplopappus venetus (COAST GOLDENBUSH); plant may contain toxic levels of nitrates.

Hedera helix (ENGLISH IVY); berries, leaves; gastrointestinal tract affected by saponins; plant also causes dermatitis.

Helenium spp. (BITTERWEED, PINGUE, RUBBERWEED, SNEEZEWEED); plant causes dermatitis.

Helianthus annuus (WILD ARTICHOKE, WILD SUNFLOWER); plant may contain toxic levels of nitrates.

HELIEBORE (Ranunculus spp.); sap; gastrointestinal tract and nervous system affected by the toxin protoanemonin; plant also causes dermatitis.

HELIOTROPE (Heliotropium spp.); entire plant; pyrrolizidine alkaloid causes hepatic veno-occlusive disease (Budd-Chiari syndrome) in humans.

Heliotropium spp. (HELIOTROPE); entire plant; pyrrolizidine alkaloid causes hepatic veno-occlusive disease (Budd-Chiari syndrome) in humans.

HELLEBORE (Helleborus niger); entire plant; cardiovascular system affected by the glycosides helleborin and helleborein; plant also causes dermatitis.

Helleborus niger (CHRISTMAS ROSE, HELLEBORE); entire plant; cardiovascular system affected by the glycosides helleborin and helleborein; plant also causes dermatitis.

HEMLOCK (Conium maculatum); entire plant, esp. roots and seeds; nervous system affected by the alkaloids coniine, conidrine, and coniceine; may contain toxic levels of nitrates; plant also causes dermatitis.

HENBANE (Hyoscyamus niger); seeds; nervous system affected by the alkaloids atropine, scopolamine, and hyoscyamine.

Heteromeles artbutifolia (CHRISTMAS-BERRY); leaves; plant is cyanogenetic.

HIGUERETA (Ricinus communis); seeds; gastrointestinal tract affected by toxalbumins; plant also causes dermatitis.

Hippobroma longiflora (HORSE POISON, MADAM FATA); entire plant; plant contains convulsants.

Hippomane mancinella (MANCHINEEL); latex; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.

Holcus lanatus (VELVET GRASS, MESQUITE GRASS); fresh or wilted plant; plant is cyanogenetic.

HOLLY (Ilex spp.); berries; gastrointestinal tract affected by saponins.

HONEYSUCKLE BUSH (Lonicera spp); berries; gastrointestinal tract, cardiovascular and nervous systems affected by plant toxins.

HORSEBEAN (Parkinsonia aculeata); plant may contain toxic levels of nitrates.

HORSEBRUSH (Tetradymia glabrata); leaves; plant is hepatogenic.

HORSE CHESTNUT (Aesculus sp.); nuts, immature growths; gastrointestinal tract affected by saponins.

HORSE NETTLE (Solanum sp.); immature growths; gastrointestinal tract affected by solanine glycoalkaloids; may contain toxic levels of nitrates; plant also causes dermatitis.

HORSE POISON (Hipponbroma longiflora); entire plant; plant contains convulsants.

HORSETAILS (Equisetum spp.); stems; toxic principles uncertain; fungi growing on plant may cause toxicity.

Hura crepitans (MONKEY PISTOL, JAVILLO, SANDBOX TREE); seeds; gastrointestinal tract affected by toxalbumins; plant also causes dermatitis.

HYACINTH (Hyacinthus orientalis); bulbs; gastrointestinal tract affected by alkaloid toxins; plant also causes dermatitis.

Hyacinthus orientalis (HYACINTH); bulbs; gastrointestinal tract affected by alkaloid toxins; plant also causes dermatitis.

Hydrangea spp. (HYDRANGEA); flower buds; plant is cyanogenetic; plant also causes dermatitis.

Hyoscyamus niger (HENBANE); seeds; nervous system affected by the alkaloids atropine, scopolamine, and hyoscyamine.

Hypericum perforatum (GOAT WEED, KLAMATH WEED, ST. JOHNSWORT); entire plant; plant causes photosensitization and contact dermatitis.

I

Ilex spp. (HOLLY, YAUPON); berries; gastrointestinal tract affected by saponins.

INDIAN HEMP (Apocynum cannabinum); leaves; plant contains cardiac glycosides.

INDIAN KALE (Xanthosoma spp.); leaves; mouth affected by irritant raphides; plant also causes dermatitis.

INDIAN POKE (Veratrum sp.); entire plant; cardiovascular system affected by alkaloid toxins; plant also causes dermatitis.

INDIAN TOBACCO (Lobelia inflata); leaves, stems, fruit; nervous system affected by pyridine, a nicotine-like toxin; plant also causes dermatitis.

INDIAN TURNIP (Arisaema triphyllum); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.

INDIA WHEAT (Fagopyrum tataricum); plant causes photosensitization.

INDIGO (Cassia sp.); entire plant; gastrointestinal tract affected by toxalbumins.

Ipomea spp. (BINDWEED, MORNING GLORIES, SWEET POTATO VINES); entire plant; plant contains LSD-related hallucinogens; may contain toxic levels of nitrates.

Iris spp. (IRIS, FLAG); rootstocks; gastrointestinal tract affected by the glycoside iridin; plant also causes dermatitis.

ITALIAN ARUM (Arum italicum); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.

J

JACK-IN-THE-PULPIT (Arisaema triphyllum, other species); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.

JAPANESE LANTERN (Physalis spp.); unripe berries; gastrointestinal tract affected by solanine glycoalkaloids.

JAPAN PLUM (Eriobotrya japonica); kernel in pit; plant is cyanogenetic.

JASMINE (Cestrum spp.); fruit, sap; gastrointestinal tract affected by solanine glycoalkaloids; nervous system affected by atropine-like toxins.

Jatropha spp. (BELLYACHE BUSH, CORAL PLANT, CURCAS BEAN, GOUT STALK, JICAMILLA, PEREGRINA, PHYSIC NUT, PURGE NUT); seeds; gastrointestinal tract affected by toxalbumins and cathartic oils; plant also causes dermatitis.

JAVA BEAN (Phaseolus lunatus); entire plant; plant is cyanogenetic.

JAVILLO (Hura crepitans); seeds; gastrointestinal tract affected by toxalbumins, plant also causes dermatitis.

JEQUIRITY BEAN (Abrus precatorius); seeds; gastrointestinal tract affected by toxalbumins.

JERUSALEM CHERRY (Solanum pseudocapsicum); immature growths; gastrointestinal tract affected by solanine glycoalkaloids; may contain toxic levels of nitrates; plant also causes dermatitis.

JETBEAD (Rhodotypos scandens); berries; plant is reputed to contain a cyanogenic glycoside.

JICAMILLA (Jatropha spp.); seeds; gastrointestinal tract affected by toxalbumins and cathartic oils, plant also causes dermatitis.

JIMMY WEED (Aplopappus heterophyllus); leaves; plant may contain toxic levels of nitrates.

JIMSON WEED (Datura stramonium); entire plant; nervous system affected by the alkaloids atropine,scopolamine, and hyoscyamine; may contain toxic levels of nitrates; plant also causes dermatitis.

JOE-PYE WEED (Eupatorium sp.); plant may contain toxic levels of nitrates.

JOHNSON GRASS (Sorghum halepense); leaves; plant is cyanogenetic.

JONQUIL (Narcissus sp.); bulbs; gastrointestinal tract affected by alkaloid toxins; plant also causes dermatitis.

Juncus inflexus (BLUE RUSH); plant causes convulsions in cattle.

K

KALE (Brassica sp.); leaves; plant is goitrogenic.

Kalmia spp. (CALICO BUSH, LAMBKILL, MOUNTAIN LAUREL, SHEEP LAUREL); leaves, nectar; gastrointestinal tract, cardiovascular and nervous systems affected by the toxins andromedotoxin and arbutin.

Karwinskia humboldtiana (BUCKTHORN, COYOTILLO); fruit; nervous system affected by plant toxins.

KENTUCKY COFFEE TREE (Gymnocladus dioicus); seeds; nervous system affected by nicotinelike toxins.

KLAMATH WEED (Hypericum perforatum); entire plant; plant causes photosensitization and contact dermatitis.

Kochia scoparia (FIREBALL, MEXICAN FIREWOOD, SUMMER CYPRESS); plant may contain toxic levels of nitrates.

L

LABRADOR TEA (Ledum spp.); leaves; plant contains toxic resins.

Labumum x watereri (GOLDENCHAINTREE, LABURNUM); entire plant, esp. seeds; nervous system affected by cytisine, a nicotine-like alkaloid.

Lactuca sariola (PRICKLY LETTUCE); plant may contain toxic levels of nitrates.

LADY SLIPPER (Cypripedium spectabiles); plant causes dermatitis.

LADY'S THUMB (Polygonum persicaria); plant may contain toxic levels of nitrates; plant also causes photosensitization and contact dermatitis.

LAMBKILL (Kalmia augustifolia); leaves, nectar; gastrointestinal tract, cardiovascular and nervous systems affected by andromedotoxin and arbutin.

LAMB'S QUARTERS (Chenopodium album); plant may contain toxic levels of nitrates.

Lantana camara (COMMON LANTANA); immature berries; nervous system affected by lantodene, an atropine-like toxin; plant is also hepatogenic.

LARKSPUR (Delphinium spp.); leaves; cardiovascular system affected by alkaloids including delphinine; plant also causes dermatitis.

Lathyrus spp. (CALEY PEA, SINGLETARY PEA, SWEET PEA, VETCHLING, WILD PEA); stems, seeds; nervous system affected by plant toxins.

LAUREL (Rhododendron spp.); leaves; cardiovascular system affected by the resinoid andromedotoxin.

LECHUGUILLA (Agave lecheguilla); plant is hepatogenic.

Ledum spp. (LABRADOR TEA); leaves; plant contains toxic resins.

LEEK (Allium tricoccum); bulbs, bulblets, flowers, stems; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.

LESSER HEMLOCK (Aethusa cynapium); entire plant; gastrointestinal tract affected by alkaloid toxins.

Leucothoe spp. (DOG HOBBLE, PEPPER BUSH, SWEET BELLS, WHITE OSIER); leaves, nectar; cardiovascular and nervous systems affected by plant toxins.

Ligustrum vulgare (COMMON PRIVET, PRIVET); entire plant; gastrointestinal tract affected by the glycoside ligustrin.

LILY-OF-THE-FIELDS (Anemone spp.); entire plant; gastrointestinal tract affected by the toxin protoanemonin.

LILY-OF-THE-VALLEY (Convallaria majalis); entire plant; cardiovascular system affected by the glycosides convallarin and convallamarin.

LIMA BEAN (Phaseolus lunatus); entire plant; plant is cyanogenetic.

LINSEED (Linum usitatissimus); entire plant, esp. immature seed pods; plant is cyanogenetic and goitrogenic.

Linum spp. (FLAX, LINSEED, YELLOW PINE FLAX); entire plant, esp. immature seed pods; plant is cyanogenetic. FLAX and LINSEED (L. usitatissimus) may contain toxic levels of nitrates, and plants are goitrogenic. YELLOW PINE FLAX (L. neomexicanum) contains saponins which affect gastrointestinal tract.

Lobelia spp. (CARDINAL FLOWER, LOBELIA, INDIAN TOBACCO); leaves, stems, fruit; nervous system affected by pyridine, a nicotine-like toxin; plant also causes dermatitis.

LOCOWEEDS (Astragalus spp., Oxytropis spp.); entire plant; may absorb toxic levels of selenium.

Lonicera spp. (HONEYSUCKLE BUSH); berries; gastrointestinal tract, cardiovascular and nervous systems affected by plant toxins.

LOQUAT (Eriobotrya japonica); kernel in pit; plant is cyanogenetic.

LORDS & LADIES (Arum maculatum); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.

Lotus corniculatus (BIRDSFOOT TREFOIL); entire plant; plant is cyanogenctic.

LUPINES (Lupinus spp.); leaves, esp. seeds; plant contains numerous alkaloid toxins including quinolizidine and piperidine.

Lupinus spp. (BLUEBONNETS, LUPINES, PURSH, SILKY LUPINE); leaves, esp. seeds; plant contains numerous alkaloid toxins including quinolizidine and piperidine.

Lycium spp. (MATRIMONY VINE); leaves; gastrointestinal tract affected by plant toxins.

Lycospersicon esculentum (TOMATO); vines, suckers; gastrointestinal tract affected by solanine glycoalkaloids.

Lygodesmia juncea (SKELETONWEED); plant may contain toxic levels of nitrates.

M

MADAM FATE (Hippobroma longiflora); entire plant; plant contains convulsants.

MALANGA (Xanthosoma spp.); leaves; mouth affected by irritant raphides; plant also causes dermatitis.

MALLOW (Malva parviflora); plant mav contain toxic levels of nitrates.

Malus spp. (APPLES); seeds; plant is cyanogenetic.

Malva parviflora (CHEESEWEED, MALLOW); plant may contain toxic levels of nitrates.

MANCHINEEL (Hippomane mancinella); latex; toxins affect gastrointestinal tract; plant also causes dermatitis.

Mandragora officinarum (MANDRAKE); nervous system affected by the toxins hyoscyamine and mandragorin.

MANDRAKE (Mandragora officinarum); nervous system affected by the toxins hyoscyamine and mandragorin.

MANGOLD (Beta vulgaris); leaves; plant contains soluble oxalates; may contain toxic levels of nitrates.

Manihot esculenta (CASSAVA); leaves, esp. Roots; plant is cyanogenetic.

MARIJUANA (Cannabis sativa); leaves, flower bracts; plant contains the hallucinogens tctrahydro-cannabinols.

MARSH MARIGOLD (Caltha palustris); entire plant, gastrointestinal tract affected by the toxin protoanemonin; plant also causes dermatitis.

MARVEL OF PERU (Mirabilis jalapa); entire plant; gastrointestinal tract affected by the alkaloid tri gonelline; plant also causes dermatitis.

MATRIMONY VINE (Lycium spp.); leaves; gastrointestinal tract affected by plant toxins.

MAY APPLE (Podophyllum peltatum); entire plant except fruit; nervous system affected by plant toxins; also cause hematological abnormalities; powdered root may cause conjunctivitis and keratitis.

MEADOW BRAKE (Onoclea sensibilis); leaves; nervous system affected by plant toxins.

MEADOW SAFFRON (Colchicum autumnale); entire plant; gastrointestinal tract affected by colchicine and other alkaloids; plant also causes dermatitis.

Medicago denticulata (BUR CLOVER); plant causes photosensitization.

Melia azedarach (BEAD TREE, CHINABERRY TREE, PRIDE-OF-INDIA); fruit, bark; plant contains convulsants.

Melilotus spp. (WHITE OR YELLOW SWEETCLOVERS); plant may contain toxic levels of nitrates.

Menispermum canadense (MOONSEED); fruit; plant contains convulsants.

Menziesia ferruginea (RUSTYLEAF); leaves; plant contains toxic resins.

MESCAL BEAN (Sophora secundiflora); seeds; nervous system affected by the nicotine-like, quinolizidine alkaloids.

MESQUITE GRASS (Holcus lanatus); fresh or wilted plant; plant is cyanogenetic.

Metopium toxiferum (POISON WOOD); plant causes dermatitis.

MEXICAN FIREWOOD (Kochia scoparia); plant may contain toxic levels of nitrates.

MEXICAN POPPY (Argemone mexicana); entire plant; isoquinoline alkaloid causes "epidemic dropsy" in humans.

MEZEREON (Daphne mezereum); entire plant, esp. fruit and seeds; gastrointestinal tract and kidneys affected by coumarin glycosides; plant also causes dermatitis.

MILK BUSH (Euphorbia spp.); latex; gastrointestinal tract affected by the toxin euphorbin; may contain toxic levels of nitrates; plant also causes dermatitis.

MILKWEEDS (Asclepias spp.); leaves, stems; plant contains toxic resins.

MINER'S LETTUCE (Montia perfoliata); plant may contain toxic levels of nitrates.

Mirabilis jalapa (FOUR O'CLOCK, MARVEL OF PERU); entire plant; gastrointestinal tract affected by the alkaloid trigonelline; plant also causes dermatitis.

MISTLETOES (Phoradendron spp.); leaves, stems, berries; gastrointestinal tract affected by toxalbumins; plant also causes dermatitis.

MOCCASIN FLOWER (Cypripedium spectabiles); plant causes dermatitis.

MOCK AZALEA (Adenium spp.); entire plant; cardiovascular system affected by digitalis-like glycosides.

MOCK ORANGE (Poncirus trifoliata); fruit; gastrointestinal tract affected by plant toxins.

Momordica spp. (BALSAM APPLE, BALSAM PEAR, BITTER GOURD, WHITE BALSAM APPLE); seeds; gastrointestinal tract affected by toxalbumins.

MONKEY PISTOL (Hura crepitans); seeds; gastrointestinal tract affected by toxalbumins.

MONKEY POD (Samonia samon); gastrointestinal tract affected by saponins; plant also causes dermatitis.

MONKSHOOD (Aconitum spp.); entire plant, esp. leaves and roots; cardiovascular svstem affected by alkaloid toxins.

Montia perfoliata (MINER'S LETTUCE); plant may contain toxic levels of nitrates.

MOONSEED (Menispermum canadense); fruit; plant contains convulsants.

MORNING GLORIES (Ipomea spp.); entire plant; plant contains LSD-related hallucinogens; may contain toxic levels of nitrates.

MOUNTAIN LAUREL (Kalmia latifolia); leaves, nectar; gastrointestinal tract, cardiovascular and nervous systems affected by the toxins andromedotoxin and arbutin.

MOUNTAIN-MAHOGANY (Cercocarpus montanus); wilted leaves; plant is cyanogenetic.

MUSHROOMS (many wild varieties); see appropriate literature for toxicities.

MUSTARD (Brassica sp.); leaves; plant is goitrogenic; may contain toxic levels of nitrates.

Myoporum laetum (no trivial [common] name in U.S.); fruit, esp.leaves; plant contains convulsants.

N

NAKED-LADY LILY (Amaryllis sp.); bulbs; gastrointestinal tract affected by alkaloid toxins.

Narcissus spp. (DAFFODIL, JONQUIL); bulbs; gastrointestinal tract affected by alkaloid toxins; plant also causes dermatitis.

Nerium oleander (OLEANDER); entire plant, and water used for cut plants; cardiovascular system affected by the glycosides oleandrin, oleandroside, and nerioside; plant also causes dermatitis.

NETTLE (Urtica procera); plant may contain toxic levels of nitrates.

Nicotiana spp. (TOBACCO, TREE TOBACCO); leaves; nervous system affected by the alkaloids nicotine and pyridine.

NIGHT-BLOOMING JESSAMINE (Cestrum nocturnum); fruit, sap; gastrointestinal tract affected by solanine glycoalkaloids; nervous system affected by atropine-like toxins.

NIGHTSHADES (Solanum spp.); immature growths; gastrointestinal tract affected by solanine glycoalkaloids; may contain toxic levels of nitrates; plant also causes dermatitis.

Nolina texana (BUNCH GRASS, SACAHUISTA); foliage; plant is hepatogenic.

NUX-VOMICA TREE (Strychnos nux-vomica); entire plant; nervous system affected by the alkaloid strychnine.

 

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The following footnotes are not contained in the Barnard book but I felt they might be helpful to readers.

1.    raphe: the ridge or line on a seed where it attaches to the ovule wall.

2.    aril: flesh, often brightly colored, cover of seed

3.    Tung: tung oil, commonly found in paints, stains, and finishes, is also toxic and such preparations should not be used in animal enclosures