“Leaves of three, leave it be.” Follow that old saw to a T, and you’ll avoid not only poison ivy, but other innocent plants like wild strawberry and jack-in-the-pulpit.
But poison ivy isn’t just a low-growing plant like these other two harmless trileaved plants-it can be a vine, a shrub, or treelike. Its leaves can be green, yellow, or red depending on the season; oval or lance-shaped; toothed, lobed, or smooth-edged; and shiny or dull. Botanists can’t even agree on how many poison ivy species exist.
And there’s more. The plant often intermingles with and is disguised by box elder, jewelweed, and hog peanut. Virginia creeper resembles poison ivy, but has five leaves.
So, then, how do you avoid poison ivy? Look not only for the plant itself, but for the “red flags” that suggest it may be nearby (see the descriptions below).
- Poison ivy
- Grows in sunny areas in open woods, along the margins of fields and trails
- Disturbed soils (pathways, campgrounds, etc.)
- The vine may look brown and shaggy
- Virginia creeper
- Grows in same areas as poison ivy
- Tendrils opposite leaves
Bees and Wasps
A variety of harmless insects fool predators by wearing the same watch-out-I-sting colors as bees and wasps. The most common mimics are syrphid flies, a family of nectar-loving impostors that are all too convincingespecially to frogs, toads, and excitable humans. Among the syrphids are the American hover fly and the drone fly.
- Bee or wasp
- Four wings (often hard to see); at rest, wings fold over the back
- Antennae longer than head
- Flight: Straight, smooth, point-to-point; hover poorly, bobbing up and down
- Syrphid fly
- Two wings; at rest, wings held slightly to the sides
- Antennae stubby, shorter than head
- Flight: Angular, zooming, hummingbirdlike; hover excellently, and can remain still in the air
Familiarity Breeds Safety
What’s the key to distinguishing the safe from the potentially harmful species?
“Familiarity,” says herpetologist Jeff Beane. “Dogs and cats both have four legs and a tail, but anybody can tell them apart, just like anybody can tell a cottonmouth from a water snake if he or she is familiar with them.” To learn to recognize the differences:
- Study flora and fauna at nature centers.
- Study nature and field guides. A good source to start with is Peterson Field Guides: Venomous Animals and Poisonous Plants, by Steven Foster and Roger Caras (Houghton Mifflin, 800-225-3362; www.backpacker.com/bookstore; $19).
- The best teacher is trail time. You’re just going to have to get into the backcountry as often as possiblefor safety’s sake, of course.