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Poisonous PlantsPoisonous Plants

Dr. Jennifer Frick-RuppertDr. Jennifer Frick-RuppertACEE Executive DirectorACEE Executive DirectorAssociate Professor of Ecology and Associate Professor of Ecology and Environmental StudiesEnvironmental Studies

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Poisonous Poisonous andand Medicinal Medicinal

Just a matter of degree!Just a matter of degree! Nicotine is a great example:Nicotine is a great example:

Cigarettes are smoked because the nicotine is a Cigarettes are smoked because the nicotine is a stimulant; it is also addictive stimulant; it is also addictive

Nicotine is extremely toxic; on par with cyanide, Nicotine is extremely toxic; on par with cyanide, heroin, atropine. heroin, atropine.

LDLD5050 is less than 5 mg per kg of body weight. is less than 5 mg per kg of body weight. Average lethal dose is 7 drops of pure nicotine.Average lethal dose is 7 drops of pure nicotine.

Nicotine content of cigarettes is regulated to a Nicotine content of cigarettes is regulated to a maximum of 1 mg per cigarette.maximum of 1 mg per cigarette.

Average human is 155 lbs or 70 kg; therefore the Average human is 155 lbs or 70 kg; therefore the LDLD5050 for a 70 kg human is about 350 mg or 350 for a 70 kg human is about 350 mg or 350 cigarettes.cigarettes.

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Some Types of Plant Some Types of Plant PoisonsPoisons Alkaloids

Derived from amino acids; basic (alkali) Most affect the nervous system because they mimic or block the action of

nerve transmitters Glycosides

Sugar-based with attached subgroup; it is the subgroup that determines toxicity

Cyanogenic glycosides release cyanide; Glucosinolates occur in mustard family; Cardiac glycosides act on heart

Oxalic acid Crystalline structure is irritating; like glass shards Rhubarb (Rheum rhabarbarum), Beets (Beta vulgaris), Sorrels (Oxalis

spp., Rumex spp.), Purslane (Portulaca oleracea); also Arum family Phenols

Acidic compounds Toxicodendron/Rhus species: Poison Ivy, Oak, and Sumac

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Edible plants and toxinsEdible plants and toxins Potato!Potato!

Solanum tuberosumSolanum tuberosum; Nightshade Family; Nightshade Family Solanine, a bitter alkaloidSolanine, a bitter alkaloid Present in green parts of leaves, sprouts and tubers; Present in green parts of leaves, sprouts and tubers;

ancestral forms even dark tubersancestral forms even dark tubers Don’t eat green potatoes!Don’t eat green potatoes!

Taro, Elephant’s EarsTaro, Elephant’s Ears Colocasia esculentaColocasia esculenta; Arum Family; Arum Family Staple food of the Pacific IslandsStaple food of the Pacific Islands Contain oxalic acid crystalsContain oxalic acid crystals Prepared by washing and pounding to make poiPrepared by washing and pounding to make poi

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Passage through Food Passage through Food ChainChain

Milk sicknessMilk sickness Cattle eat White Snakeroot (Cattle eat White Snakeroot (Eupatorium rugosumEupatorium rugosum)) Milk from these cows sicken peopleMilk from these cows sicken people Common disease in eastern states; Lincoln’s Common disease in eastern states; Lincoln’s

mother, my neighbors!mother, my neighbors! Several compounds including glycosides and a Several compounds including glycosides and a

complex alcohol (tremetol)complex alcohol (tremetol) Turtles and poisonous mushroomsTurtles and poisonous mushrooms

Turtles unaffected; humans that eat the turtles can Turtles unaffected; humans that eat the turtles can be sickenedbe sickened

                                             

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Fungal Pathogens on Fungal Pathogens on FoodFood Ergot poisoningErgot poisoning

Fungus (Claviceps spp.) growing on Rye or Wheat or other grasses; humans eat the flour

Ascomycete fungus; makes a hard black elongated structure Grain containing more than 0.3% ergot is prohibited from sale Over 40 alkaloids present; related to lysergic acid Symptoms include irritable digestive tract, loss of balance,

convulsions, drowsiness Witch-hunts of Salem and other towns

Aflatoxins/MycotoxinsAflatoxins/Mycotoxins Contaminants of grain or other foods Penicillium, Aspergillus, Monascus commonly Confusion between plant toxicity and mold toxicity

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FoxgloveFoxglove

Digitalis purpurea; Digitalis purpurea; Figwort FamilyFigwort Family Native to England and Europe; naturalized in Native to England and Europe; naturalized in

USA; planted in gardensUSA; planted in gardens Contains a cardiac glycosideContains a cardiac glycoside Used to treat “dropsy:” massive fluid retention Used to treat “dropsy:” massive fluid retention

caused by poor heart functioncaused by poor heart function Now used in controlled dosages to correct Now used in controlled dosages to correct

heart beat irregularities, improve circulation, heart beat irregularities, improve circulation, relieve fluid buildup, help kidney function relieve fluid buildup, help kidney function

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MayappleMayapple

Podophyllum peltatum; Podophyllum peltatum; Barberry FamilyBarberry Family Natives used as emetic and worm Natives used as emetic and worm

expellent; also for syphilisexpellent; also for syphilis Strongly irritating to skin and poisonousStrongly irritating to skin and poisonous Contains lignans with anti-cancer and Contains lignans with anti-cancer and

anti-viral propertiesanti-viral properties Used today to treat venereal warts and Used today to treat venereal warts and

testicular cancertesticular cancer

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BuckeyeBuckeye

AesculusAesculus spp.; Horse Chestnut Family spp.; Horse Chestnut Family Main toxin is a saponin glycoside Main toxin is a saponin glycoside

(aesculin)(aesculin) All parts of plant toxicAll parts of plant toxic Natives used ground leaves to kill fishNatives used ground leaves to kill fish

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Cherries, Peaches, Plums, Cherries, Peaches, Plums,

PrunusPrunus spp. Rose Family spp. Rose Family Leaves, bark, and seeds (but not fruits) are Leaves, bark, and seeds (but not fruits) are

toxictoxic Contain a cyanogenic glycoside (amygdalin) Contain a cyanogenic glycoside (amygdalin)

resulting in cyanide poisoning if ingestedresulting in cyanide poisoning if ingested Almonds are the seeds of a species of Almonds are the seeds of a species of PrunusPrunus

that produces low levels of toxinthat produces low levels of toxin

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Poison Ivy, Oak, SumacPoison Ivy, Oak, Sumac ToxicodendronToxicodendron or or RhusRhus spp. Cashew Family spp. Cashew Family Variable growth form; climbing or bushyVariable growth form; climbing or bushy Leaflets in 3 on compound leaves; alternate leavesLeaflets in 3 on compound leaves; alternate leaves Contains an oleoresin (urushiol) in sap; pollen or Contains an oleoresin (urushiol) in sap; pollen or

smoke also irritatingsmoke also irritating Poison Sumac has alternate, pinnately compound Poison Sumac has alternate, pinnately compound

leavesleaves Don’t confuse with Virginia CreeperDon’t confuse with Virginia Creeper

5-parted leaves5-parted leaves

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Dolls-Eyes or BaneberryDolls-Eyes or Baneberry

Actaea pachypodaActaea pachypoda and and A. rubraA. rubra; ; Buttercup FamilyButtercup Family

All parts toxic, especially berries and All parts toxic, especially berries and rootsroots

Undetermined toxin, probably a glycosideUndetermined toxin, probably a glycoside Used by natives as emetic Used by natives as emetic

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BloodrootBloodroot

Sanguinaria canadensisSanguinaria canadensis; Poppy Family; Poppy Family Contains several alkaloids including Contains several alkaloids including

sanguinarine; very toxicsanguinarine; very toxic Used to induce glaucoma in laboratory Used to induce glaucoma in laboratory

animalsanimals

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False HelleboreFalse Hellebore

Veratrum parviflorumVeratrum parviflorum and others; Lily and others; Lily FamilyFamily

Contain several alkaloids including Contain several alkaloids including veratridineveratridine

Can be mistaken for other plants, Can be mistaken for other plants, including edible Rampsincluding edible Ramps

Used to treat high blood pressureUsed to treat high blood pressure

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Poison HemlockPoison Hemlock

Conium maculatumConium maculatum and and CicutaCicuta spp.; Umbel spp.; Umbel FamilyFamily

NOT the Hemlock tree (NOT the Hemlock tree (Tsuga canadensisTsuga canadensis)) Resembles wild carrot, but has smooth leavesResembles wild carrot, but has smooth leaves Used to poison SocratesUsed to poison Socrates European weed, now naturalized USAEuropean weed, now naturalized USA Contains toxic alkaloids related to nicotineContains toxic alkaloids related to nicotine

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PokeweedPokeweed

Phytolacca americanaPhytolacca americana; Pokeweed Family; Pokeweed Family Several toxic compounds, mostly Several toxic compounds, mostly

saponins, but recently a mitogen that saponins, but recently a mitogen that damages blood cellsdamages blood cells

Young stalks commonly eaten after Young stalks commonly eaten after boiling in several watersboiling in several waters

No longer recommendedNo longer recommended

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ReferencesReferences

NJ Turner and AF Szczawinski. 1991. NJ Turner and AF Szczawinski. 1991. Common Common Poisonous Plants and Mushrooms of North Poisonous Plants and Mushrooms of North AmericaAmerica. Timber Press, Oregon.. Timber Press, Oregon.

S Foster and JA Duke. 1990. S Foster and JA Duke. 1990. Peterson Field Peterson Field Guides Eastern/Central Medicinal Guides Eastern/Central Medicinal PlantsPlants.Houghton Mifflin Company, Boston..Houghton Mifflin Company, Boston.

A Krochmal and C Krochmal. 1984. A Krochmal and C Krochmal. 1984. A Field A Field Guide to Medicinal PlantsGuide to Medicinal Plants. Random House, NY.. Random House, NY.

Most of the photos in this presentation were Most of the photos in this presentation were from these references or from various internet from these references or from various internet sites. Do not distribute them.sites. Do not distribute them.