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Ibet you would need to go to a rather remote placeon the planet to find someone who is not familiarwith this song. And it would be harder to find any -one in the South who has not had an experience with theplant itself. For the lucky ones, perhaps the experienceis only through a family member or classmate. In thatcase often a good laugh, right? If there were some wayto tally up all the negative encounters with hornets,bees, poisonous snakes, sharks, disease-bearing ticks,skunks, jellyfish stings, lighting and perhaps even fireants, I suspect rashes from poison ivy would outscoretheir combined suffrage.

Poison ivy is but one of over 700 North Americanplants known to be toxic to people or livestock. Thelist includes algae, fungi, lichens, ferns, horsetails, certainpines and various flowering plants. The majority of theseare poisonous only if eaten, but poison ivy and its rel a -tives are unusual in that their poison can be trans mittedby simple contact with the plant. Did you ever wonderabout all the products that boast “made of 100 percentnatural ingredients?” Well, perhaps you should, becausetoxic plants are packed with only natural substances.So here is a little hint, don’t try to eat poison ivy, the all-natural plant, as it can get you that way too.

Poison ivy, a ubiquitous species, grows throughoutmost parts of the eastern and central United States andsouthern Canada. It is found throughout the South.People become confused because this plant does notalways take on its ivy-like growth habit. Poison ivy cangrow into an ivy-like vine, a woody shrub or simply aslittle woody stems poking upward from the forest floor.

The syndromes caused by poison ivy have beenknown since the days of Captain John Smith and theyhave been described in various American Indian cultures.This plant was one of the earliest formally named NorthAmerican species when Jacob Cornutus described it inhis “Plantarum Canadensis” in 1635. Since then the tax -onomic name has been revised several times, and thecurrent name for the genus does not even have a Latinequivalent and dates back to one used by ancient Greeksfor Old World plants with similar toxic traits.

“Leaves of three, let it be.” This seeminglyinnocuous vine has been the scourge ofcountless outdoor enthusiasts.

Poison Iv-y-y-y-yMeasles make you bumpy

And mumps’ll make you lumpy

And chicken pox’ll make you jump and twitch

A common cold’ll fool ya º

And whooping cough can cool ya

But poison ivy, Lord’ll make you itch!!

©Jerry Leiber & Mike Stoller, 1959

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exposure is from contact with the toxinsthem selves, and generally not contact withthe rash that develops later.

• Inhalation of airborne urushiol thatcan occur when a lawnmower or trimmer isused to cut down poison ivy vines or shrubs.Inhalation of urushiol causes the rash toappear on the lining of the lungs causingsevere pain and respiratory dis tress.

• Inhalation of smoke from burningpoison ivy.

• Eating poison ivy.• While it is widely believed that one can

infect other areas of their body from the weep -ing blisters or that it spreads from scratching,this is not generally believed to be the case.Nor can people spread the infection from oneperson to another. Fluids oozing out from theblisters cannot spread the rash on you or toanother person. The oozing blisters are mostly

just body fluids. But be careful of what youlearn from books. I know a colleague thatpublished a paper in the prestigious medicaljournal, The Lancet, on infection to his partneras a result of sexual transfer. Bet you neverthought of poison ivy rash as a sexually trans -mitted disease. Good science experimentsneed to be confirmed by replicate research, butI am unable to find anything in the medicalliterature about follow-up studies. I suspectresearchers had trouble recruiting volunteersfor the follow-ups. I may be wrong but I betsome college students would raise their hands.

Poison ivy most often has groups of threeleaves, but it may have five or seven. Theleaves may be notched or have smoothedges. Poison ivy berries become glossywhen ripe. A big hairy vine growing up atree is a very visible warning sign.

I was never one to dwell on the symbolic.I recall a final exam in American literaturewhere the entire grade rested on answeringthe question “Explain the religious symbolismin Steinbeck’s “Grapes of Wrath.” While thiswas intended to be a multi-level question myanswer was short and simple “You guys couldfind religious symbolism in a Batman comicbook!” I aced the test. I was in high schoolwhen The Coasters’ “Poison Ivy” hit thecharts, and because of my disregard for thesymbolic even back then, I did not have anyreason to believe that the lyrics were aboutanything but the rashes produced by theplant. Now I find out that many suspect thesong is not about a plant at all, but rather a young lady with a social disease. The ironyof my colleague’s published findings can’tbe ignored.

And speaking of Batman comic books andfemales that make you itch, the idea of poisonivy being an evil female surfaces again. PoisonIvy, one of the more toxic of the Gotham Cityvillains, is portrayed as an eco-terrorist, pro -tecting the environment in ways that requireBatman’s intervention. Wearing her sexy ivy

She comes on like a rose but everybody knows She’ll get you in Dutch

You can look but you better not touch

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So here are the ABCs of concerned people’smost frequent questions.

How does the poison work? The plant produces an organic oil calledurush iol which causes an allergic skin rashon contact. This is known medically asurushiol-induced contact dermatitis. Theskin rash causes intense itching and leads tothe formation of blisters. Open blisters leadto sores and these sores can become infected.The urushiol produced by poison ivy is verypotent and can remain active for several yearsafter the plant is dead.

The toxin is a colorless to milky substancethat is contained in the resin canals of theplant. It is found throughout the plant—roots, stems, leaves, flowers and fruits—andis only absent from the plant’s pollen. Thechemistry of the toxic substance is a 3-n-pentadccylcatechol, and the sensitizingcompounds are alkylated dihydroxy phends.

See, you should have paid attention in organicchemistry class. There are actually four dif -ferent poisons in the chemical chain. Thecombination of the toxin with skin proteinsstarts the reaction.

The words poisonous and toxic are usedinterchangeably even in the circular defini -tions of dictionaries. Biologically plants andanimals that contain poison are poisonous(rattlesnakes, spiders, gila monsters, poisondart frogs, jellyfish, and mushrooms forinstance). The poison can be injected oringest ed. Toxic plants and animals are onesthat secrete chemicals that then react withchemicals in our bodies (toxic plants, chig -gers, licking toads and inhaling chemicalfumes). But there are all sorts gray areas, andsome things could be toxic to your skin andpoisonous if you ate them. And then there isnuclear poisoning and all the various deadlytransgressions they do in James Bond movies.So I think most people have just given up and

use whichever term gets the best attention.But if you come in contact with toxic ivy ortoxic oak there is probably no immediate needto call the Poison Control Center ’s hot line.

OK, it can be bad stuff; so how can I avoid it? You can stay indoors or perhaps move toGreenland. Otherwise it’s hard to stay awayfrom poison ivy, as it grows pretty mucheverywhere. Your best bet is to learn to iden -ti fy the plant. The plant’s appearance can bedeceptive because of its various growth forms.

The leaflets of poison ivy are usuallyarranged in groups of three, but they mayalso appear in fives or sevens. In each cluster,the middle leaflet grows on a stalk that ismuch longer than those on the sides. Theleaflets in the compound leaf are usuallyfairly equal in size, but the individual leafletscan vary greatly in size—from one-half to2 inches long. Their edges may be slightly

notched or smooth. Theyare shiny when young andturn a brilliant red in fall. Theflowers of poison ivy are yel -lowish to greenish-white, aboutone-quarter inch in diameterand grow in clusters on a slen -der stem. Small, berry-like,whitish or greenish fruit, about

one-sixth of an inch across, appears after theflowers have faded and are glossy when ripe.

What about similar appearing non-poisonous plants?OK, so you have no desire to become aback yard botanist. Just avoid anything youthink might be poison ivy. Recall all the funevery one had at summer camp when poisonivy was an endless source of pranks andjokes, mostly at others’ expense. But youcan learn to distinguish poison ivy fromother native plants by means other than atrial-and-error approach.

There are a number of woody vines andshrubs that have compound leaves that aresuperficially similar to poison ivy. Many ofthem grow in the same habitats, often sideby side with poison ivy. The trifoliate (threeleaflets) leaves of poison ivy are arranged inan alternate fashion, and this combinationalone eliminates many of the plants that one

might confuse with poison ivy. Additionally,other plants have a variety of flowers, fruitsand seedpods that are not anything like thesmall greenish white flowers or the whiteberries—actually drupes—of poison ivy.The simplest thing is to just learn what poisonivy looks like and then avoid any plant thatyou think even looks like it.

What other toxic plants do we need to worry about?Other poisonous plants similar to the poisonivy include poison oak and poison sumac.For many people, including botanists, thereis some confusion regarding names of ourtoxic plants. This won’t help one bit, but youshould know that poison ivy is not an ivy andpoison oak is not an oak. They, like poisonsumac and other sumacs, are members ofthe family Anacardiaceae.

In its shrub form, poison ivy is often calledpoison oak. Then there is a second speciesalso found in the South that is named poisonoak. It never takes on vine-like growth; it’ssimply a plant with woody stems that growsin dry sandy habitats where poison ivy doesnot grow. Many botanists believe that this“poison oak” is simply a variety of poisonivy and not a true species. True poison oakis a plant found only on the Pacific Coast ofthe United States and of Canada. Our poisonoak is found in dry woodlands, thickets andabandoned fields of the Coastal Plain andlower Piedmont. And then there is poisonsumac, another plant closely related to poisonivy. It grows in swamps, bogs and pocosinsin the eastern North America. It can grow upto 15 feet in height, and like other sumacshas compound leaves with seven–11 leaflets.

How Does One Get Poison Ivy?The following are the ways by which poisonivy can infect the body:

• Skin contact with a poison ivy vine orshrub, with secondary spreading to other skinsurfaces by urushiol on the sufferer ’s hands.Try to avoid rubbing eyes with your hands.

• Skin contact with items such as clothingor garden tools that have been exposed tourushiol from poison ivy.

• Skin contact with people or animals thathave been exposed to poison ivy. Animals areusually immune to poison ivy. Secondary

She’s pretty as a daisy but look out man she’s crazy She’ll really do you in If you let her under your skin

it-alls, who everyone, including the teacherhates. Well we know from experience thatthey really do exist and it’s an unusual classthat does not have at least one. I had the goodfortune to have one in my college botany class,and then another years later in a class I wasteaching, who each took delight in showingeveryone on respective field trips that theywere immune and vigorously rubbed poisonivy leaves on their arms and legs. In the daysthat followed it was clear that they were mis -taken about their super powers, and we allacquired a new level of appreciation for theplant. OK, I probably should have informedmy student of the changing nature of one’sbody reaction to the plant, but it’s hard toignore a good teaching moment. You have gotto love nature.

Actually no one gets a reaction on firstexpo sure, but your body becomes sensitizedto it, and some people require repeated expo -sures before their skin reacts to the plant’s oils.However, most if not all people who continueto have no allergic response will become sensi -tized over time with repeated or concentratedexposure to urushiol. Studies conducted inthe mid-70s showed that about 40 percent ofpeople exposed to the quantity of urushiol injust a piece of a leaf one-quarter inch in dia -meter will have a reaction. This increases toabout 75 percent in stronger doses.

Even minor reactions are annoying andunpleas ant. You can always just scratch, butit does not do a bit of good, although it feelsgood while you are doing it. You do have tobe concerned about the secondary skin infec -tions resulting from your scratching later.

Some Other Stuff You Might Want to Know To those susceptible to poison ivy the newsis increasingly bad. As a result of land clearingand global warming, the plant is increasingin abundance and toxicity. Poison ivy needssun and it thrives in open situations and alongthe edges of woodlands. In our yard in Raleigh,the plant was everywhere when we purchasedthe property in the mid-70s, but as the forestmatured and the property became more shad -ed it mostly died out. Today the plant growsentirely near the edges of our woods in theform of large woody vines. The ivy climbshigh into the pines and oaks, vines the size

TreatmentWithout treatment thedermatitis will clear up in10 to 21 days. Dependingon the severity, contem -porary treatment optionsare as follows:

1. Removal of the antigenfrom the skin with alcoholor alkali soap.

2. Application of cold watercompresses to alleviateinflammation.

3. Applying commerciallotions to reduce itching.

4. Local or systemic adminis -tration of cortisone drugs.

5. Use of antihistaminicdrugs to reduce itching.

6. Use of antibiotics to mini mize secondarybacterial infections.

of my arms climb 40 feet and more into ourtrees. Back in the woods, 20 to 30 feet awayfrom the edges, the ivy totally disappeared.Global warming is altogether another issue.Warmer temperatures makes plants moretoxic, as does increased levels of carbondiox ide. Both have a positive effect on theconcentrations of urushiol. Years back, thefirst summer I worked in Florida, I had anextremely bad reaction to poison ivy. At thetime I did not understand why the same plantthat had I frequently encountered many timesin Maryland with mild reactions, in Floridacaused severe swelling and large oozing blis -ters. Studies comparing the chemical compo -sition of the principal active components ofthe urushiol in poison ivy leaves from NewYork, Maryland and Mississippi showed thatthere is considerable geographic variation inthe plant’s potency.

The plant is not without merit. Poison ivyis a native species and it does have ecologicalutility. A number of songbirds eat the berriesin the winter. Downy woodpeckers also eatthe berries and deer can eat the poison ivyplants and not be affected by the toxins. Birdsthat feed on the plant’s fruit disperse theseeds in their droppings. Since I like listeningto the songbirds, enjoy watching woodpeckersand deer and like venison, I guess the fact thatthese animals may find poison ivy enjoyableto eat gives the plant someredemp tion—but notmuch. In the fall the redhues of their colorful leavesadd contrasting colors to falllandscapes. And for those ofus who enjoy the outdoors, weneed to appreciate poison ivy,poisonous snakes, hornets, bitinginsects, skunks and bears. There are vast numbers of people who neverventure into the woods. The biting,stinging and irri tat ing flora and faunacollectively act to keep city folks andtheir unattended children out of ourwoodlands and in shop ping malls,bowling alleys and at home with their video games.

Regular contributor David S. Lee is director ofthe Tortoise Reserve, an international turtleconservation organization.

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So to make sure my advice was on the righttrack I brought my questions to my localphar macy, Anderson Drug Store in Elizabeth -town. Since this is a small pharmacy, not a big-box drug store, pharmacist Gene Andersonactu ally took the time to talk to me. He in -formed me that Burrow’s solution helps todry weep ing sores. Oatmeal baths (Aveeno)and cala mine lotion help to reduce itching ifthe lesions are dry. Avoid dressings as exposedskin will heal faster. If more than 25 percentof the body is involved then prescribed oralsteroids may be in order.

Remember there is no known cure. Insevere cases physicians may administersome cortisone derivative under carefullycontrolled conditions. For people especiallyprone to poison ivy, prevention by pre-expo -sure oral medications taken several monthsprior to contact are available, but the resultsare controversial and may have little effect.Severe exposure to the plant is serious, andsecondary infections and other complica tions

are likely. On occasion exposure can havelethal results.

Many people who frequent the outdoorsand find themselves exposed to poison ivywill rub the exposed area of their skin withthe crushed leaves of jewel weed. Jewel weedcan often be found in areas where poison ivygrows, so this is a quick and handy solution.OK, so now you need to learn what two plantslook like, and since you obviously did not do agood job on learning Rhus radicans, you prob -ably are not yet on a fast track to becoming abotanist. Jewel weed seems to work if donewithin minutes after exposure, but this prob a -bly varies somewhat based on an individual’ssensitivity to the toxin in poison ivy.

Not everyone who comes in contact withpoison ivy reacts to it, and only about halfthe population is sensitive to mild contactwith the plant. Somewhere between 15 and30 percent of the population is immune, orthink they are. Recall the stereotype of themale student in movies; loud, brash know-

wardrobe, her prominence grew in both thecomic books and films as the feminism move -ment even created a demand for botanicalfemale super villains. So let’s never under esti -mate the powers of poison ivy.

What can I do if I get it? There actually is no cure, so prevention is stillyour best bet. Learn what the plant looks like,and wear sensible clothes when hiking andcamping in the woods. To help learn the plantthere are a couple of simple but helpful say -ings: “Leaves of three, let it be.” “Berrieswhite, take flight.”

Oh, no, I got it. Washing with soap willserve to remove the excess urushiol that couldbe translocated to other parts of the body orto other persons. For those who find you for -got to put the bar of yellow soap and bucketof warm water in your backpack there are anynumber of after-the-fact topical lotions andcreams which soothe the itching and to somedegree dry and control the extent of blistering.

Although often thought of growing as avine, in some spaces poison ivy will growas a shrub up to 3 feet tall.