COMMON ST. JOHN'S-WORT (HYPERICUM PERFORATUM)

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St.-John’s-wort (Hypericum) includes both native plants and introduced weeds, the commonest of which is the European Hypericum perforatum. This rangy opportunist has invaded roadsides, pastures, and cutover forest all across Nova Scotia.

The golden-yellow flowers bloom profusely in midsummer. If you pick the opposite leaves and hold them up to the sunlight, you can see they are marked with many little, translucent dots, which can be the source of serious skin irritations.

In Teutonic mythology, the plants were associated with the sun god, Baldur, whose festival was held annually around June 24, when the sun is in the sky longer than at any other time of the year.

With the ascendancy of Christianity, Baldur lost out, and his date was assigned to the feast day of St. John the Baptist. So, Baldur’s sunny yellow flowers became dedicated to the “voice crying in the wilderness.”

The herbal term wort has medical significance. It is a corruption of the Old English wyrt, which is Anglo-Saxon for “useful pot-herb.” In ancient medicine, St.-John’s-wort was renowned as a vulnerary—a remedy for the healing of wounds—as well as for internal applications.

Currently, it is used in psychiatry and herbal medicine in the treatment of various depression disorders (hyperforin). Care must be taken in using products containing hypericin; once light sensitivity is induced, it cannot be easily reversed.

Livestock grazing pastures infested with this plant and their agricultural attendants run a high risk of repeated exposure.

Other, native species of Hypericum contain various amounts of hypericin, but the introduced weed is the most problematic.

POISON LOCATION

Leaves and stems contain the latex.

POISON TYPE

The sap (sticky latex) contains several glycosides, the quantity and efficacy depending upon the species.

TYPICAL POISONING SCENARIO

Consumption of leaves and stems, by children or those seeking a herbal cure.

SYMPTOMS

The glycosides are generally cathartic (purgative, laxative).

COMMON ST. JOHN'S-WORT POISON INFORMATION

Phototoxins

Phototoxins are chemical substances that make the skin very sensitive to the ultraviolet radiation in sunlight and other light sources.

SEE ALSO

Bracken Fern

Aloe

POISON PLANT LOOKUP

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Choose Plant Family --------------------------------- Algues toxiquesAloe FamilyAmanita FamilyAmanita Family2Amaryllis FamilyArum FamilyBean FamilyBirch FamilyBuckeye FamilyBuckwheat FamilyButtercup FamilyCashew FamilyFlax FamilyFumitory FamilyHeath FamilyHolly FamilyHoneysuckle FamilyHymenogastraceaeHymenogastraceae FamilyLily FamilyMagic MushroomsMagic Mushrooms2Magic Mushrooms3Mezereum FamilyNightshade FamilyParsley FamilyPlantain FamilyPoisonous AlgaePoisonous AlgaePoppy FamilyRose FamilySensitive-fern FamilySnapdragon FamilySpurge FamilySt. Johns-wort FamilySunflower FamilyYew Family

Choose Common Plant --------------------------------- AlderAloeAutumn CrocusBaneberryBleeding HeartBloodrootBracken FernBuckwheatButtercupCaladiumCastor BeanCherry, Chokecherry, PlumCloverCommon St. John's-wortConocybeCrotonCrown-of-thornsDaffodilDaphneDeadly GalerinaDestroying AngelDumbcaneElderberryEnglish HollyFalse HelleboreFlaxFly AgaricFoxgloveGolden ChainHorse-chestnutJack-in-the-pulpit; Indian TurnipJimsonweedLaceleafLarkspur and MonkshoodLiberty CapLily of the valleyLocustLupin or LupineMarsh-marigoldNightshade, BittersweetPanaeolusPhilodendronPlantainPoinsettiaPoison HemlockPoison IvyPoppyRagweedRed TideRhododendron, Rhodora, AzaleaRhubarbScillaScotch BroomSkunk-cabbageSnow-on-the-mountainStar of BethlehemSun SpurgeTansy RagwortTulipVirgin's-bowerWater-hemlock; CowbaneWinterberry, Canada HollyWormwoodYew

Choose Botanical Plant --------------------------------- Actaea speciesAesculus hippocastanumAlnus speciesAloe barbadensisAmanita muscariaAmanita virosaAmbrosia speciesAnthurium speciesArisaema triphyllumArtemisia speciesCaladiumCaltha palustrisCicuta maculataClematis speciesCodiaeum variegatumColchicum autumnaleConium maculatumConocybeConvallaria speciesCytisus scopariusDaphne mezereumDatura stramoniumDelphinium and AconitumDicentra formosaDieffenbachia speciesDigitalis purpureaEndymion speciesEuphorbia helioscopiaEuphorbia marginataFagopyrum esculentumGalerina AutumnalisHypericum perforatumIlex aquifoliumIlex verticillataKoeberlinia species; Euphorbia speciesLaburnum speciesLinum speciesLupinus speciesNarcissus speciesOrnithogalumPanaeolus speciesPapaver speciesPhilodendron speciesPlantago speciesPoinsettiaPrunus speciesPsilocybe pelliculosa, P. semilanceolataPteridium aquilinumRanunculus speciesRed TideRheum rhabarbarumRhododendron speciesRicinus communisRobinia speciesSambucus speciesSanguinaria canadensisSenecio jacobaeaSolanum dulcamaraSymplocarpus foetidusTaxus speciesToxicodendron radicansTrifolium speciesTulipaVeratrum species

Choose Poison Type --------------------------------- AlcoholAlkaloidsCarcinogens and co-carcinogensGlycosidesHay Fever allergensOxalatesPhenolsPhototoxinsProteins and Amino AcidsResins and Volatile OilsShellfish Poisons

Common Lookups

Poison Ivy

Red Tide

Buttercups

Ragweed

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