Poison ivy has its place in ecosystem

By George Ellison
Citizen-Times Correspondent
November 15, 2008

If you like native plants that are variable and adaptive, have interesting natural histories with abundant associations in both Cherokee and early white settler folklore, add immeasurably to the fall landscape with vivid colors and provide nutritious fare for over-wintering birds, why then poison ivy is surely one of your favorites.

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 the plant with respect as hi-ginalii, or my friend, rubbed it on the beaten flesh of a crawfish. The early settlers applied crushed jewelweed (touch-me-not) stems and leaves a remedy utilized by many to this day.

Other remedies have featured Vaseline, salt, baking powder or diluted bleach. The late 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 best antidote, for me, is one that I only discovered in recent years. That's Dawn dish detergent. Something in that brand of detergent, which is also a degreaser, almost completely neutralizes the effects of urushiol on my skin. I apply the detergent liberally to the irritated area and let it dry.

Poison ivy flowers rather inconspicuously from May to July in clusters of small greenish flowers. I like to observe the plant in fall and early winter when its leaves turn wine red or crimson as a signal to birds that its 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. 

More than 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. It's all in the eye of the beholder.

George Ellison is a naturalist and writer. His wife, Elizabeth Ellison, is a watercolor artist and papermaker who has a gallery-studio in Bryson City. Contact them at info@georgeellison. com or info@elizabeth ellisonwatercolors.com or write to P.O. Box 1262, Bryson City, NC 28713.

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