“Leaves of three, let it be.” That old-time homily for a plant that has been labeled “the botanical Judas” is useful, if botanically inaccurate. What may appear to be three leaves is actually one leaf divided into three parts.

Poison ivy is such a variable plant in its growth patterns that you’re often into a stand before realizing that you’re surrounded by “leaflets of three.”

These leaflets can be from under one to over four inches in length, elongated or almost rounded, and hairy or smooth, with edges that can range from softly lobed to notched. To make matters more confusing poison ivy can appear as a creeping ground cover, a shrub, or as a vigorous vine in habitats that range from dry and open to moist and shady.

But once you get “the feel” for poison ivy, you can often “sense” its presence just as you can sometimes intuit the presence of a snake. Note the slightly asymmetrical structure of the leaves combined with the fact that the central leaf has a short stem. Some confuse it with Virginia creeper. But that plant displays five leaflets.

Poison ivy’s toxic power sometimes assumes legendary proportions even in otherwise understated medical literature. The culprit is urushiol — a resinous sap-like oil found in the roots, stems, leaves, flowers, and fruit — which probably evolved as a chemical defense mechanism against browsing herbivores. It’s so powerful that one part mixed with 60,000 parts olive oil is said to still cause infection.

You can pick it up from contact with the plant’s surface features (especially bruised or moist leaves), while handling cut vines or roots, and even from particles carried in smoke and inhaled when the plant is being burned miles away. The oil can remain active for four months or more on tools, sporting equipment (including golf balls), clothing, or a pet’s fur.

For those who are highly susceptible to the poisoning, the effects can sometimes be devastating and require extensive professional treatment. Old-time remedies abound. The Cherokee — who addressed it with respect as “hi-ginalii” or “my friend” — either rubbed on the beaten flesh of a crawfish or applied the juice from seven blossoms of jewelweed. The early white settlers applied crushed jewelweed stems and leaves — a remedy utilized by many to this day. Other old-time antidotes included the use of boiled milkweed, a potentially powerful concoction comprised of buttermilk and gunpowder, a mixture of vinegar and salt, and a mixture of soap and wood ashes.

More recent remedies have featured vaseline and salt, baking powder, or diluted bleach. Bryson City author Horace Kephart in his classic 1906 outdoor book titled Camping and Woodcraft recommended a solution of baking soda in warm water followed by a good ointment. My grandmother applied calamine lotion without delay.

But the very best antidote, for me, is one that I only discovered within recent years. That’s Dawn dish detergent. Something in that brand of detergent, which is also a degreaser, completely neutralizes the effects of urushiol on my skin. I apply the detergent liberally to the irritated area and let it dry. After just a few minutes there is almost immediate relief. And after an hour or so the irritation is eradicated. Try it and see if it works for you.

Poison ivy flowers rather inconspicuously from May to July in clusters of small greenish flowers. I like to observe the plant in early fall when its leaves turn wine red or crimson as a signal to birds that the gray-white berries are available for consumption.

Other plants like Virginia creeper, sassafras, spicebush, dogwood, buckeye, and the sumacs also display an early flush of leaf color as a means of standing out against the prevalent leafy background so as to obtain a head start in regard to seed dispersal. Biologists call this phenomenon “foliar fruit flagging.” Over 60 species of birds have been observed devouring poison ivy berries.

I also enjoy observing poison ivy during the winter months, when the bare, shaggy vines — which can be wrist thick —can be clearly viewed against the trunks of trees and suspended high above in the outreaching branches. Black locust seems to be a frequent host, probably because that tree’s deeply furrowed bark affords the vine with a ready foothold.

For me, the plant lends a sinuous but not a sinister aspect to the winter landscape. But as in most other matters, it’s all in the eye of the beholder.

George Ellison wrote the biographical introductions for the reissues of two Appalachian classics: Horace Kephart’s Our Southern Highlanders and James Mooney’s History, Myths, and Sacred Formulas of the Cherokees. In June 2005, a selection of his Back Then columns was published by The History Press in Charleston as Mountain Passages: Natural and Cultural History of Western North Carolina and the Great Smoky Mountains. Readers can contact him at P.O. Box 1262, Bryson City, N.C., 28713, or at This email address is being protected from spambots. You need JavaScript enabled to view it..