So goes the easy-to-remember rhyme that’s supposed to help you identify the infamous Poison Ivy plant.
Touching poison ivy can cause extraordinarily unpleasant itchy blisters. Therefore, identifying this species is an important outdoor skill.
While memorable, the popular rhyme lacks detail.
Should you avoid all plants with three leaves? What if it doesn’t have white fruits? What should you do if you think you have touched it?
If you head out into nature and want to return home itch-free, you’ve found the right blog!
Identify poison ivy
Many plants have three leaves or leaflets. How to distinguish Poison Ivy from the rest?
Poison ivy leaves separate into three brochures (Each “leaf of three” is technically a single sheet.) This is known as a compound leaf, like the leaves of ash and walnut trees.
Two of the leaflets are connected to the petiole (leaf stem) facing each other, while the middle leaflet is connected further outwards on the petiole.
Poison Ivy is not the only species that fits this description; brambles (raspberry and blackberry species) and Hog Peanut look alike, although the stems of brambles are covered with thorns or thorns.
Would you identify this as Poison Ivy?
Unlike brambles, the stem we are looking for is woody and thornless.
To complicate matters a bit, Poison Ivy leaflets can appear in a variety of forms.
Their edges vary from smooth to very serrated and can be lobed or unlobed.
In spring, the leaves are usually reddish green or tan before turning bright green in the summer.
Poison ivy grows clusters of small greenish-white flowers in the spring, eventually giving rise to berry-like fruits in the summer, which range from gray to white in color and are usually waxy.
Am I safe in the winter?
Unfortunately, you’ll have to be on the lookout no matter the season.
All parts of the poison ivy plant, including the leaves, berries, and stems, contain urishurol, the substance that causes an itchy rash if most humans touch it.
That is why it is important to know what the plant looks like in all seasons.
Poison ivy in winter
Come fall, poison ivy plants exposed to the sun will see their leaves change to a bright orange-red or burgundy wine red color.
In shaded areas, they will turn a dull brown color.
The woody stem of poison ivy persists through the winter. The plants often carpet the forest floor in dense, low clumps. But sometimes they climb tree trunks or are two to three feet tall.
Why don’t you get rid of him?
Poison ivy thrives in disturbed places.
It often loves the edges of trails and campsites, or trampled areas such as social trails.
If we try to pull it out or spray it, we are creating more of the conditions this plant likes, while destroying the more sensitive neighboring plants that prevent Poison Ivy from completely dominating the area.
Additionally, since poison ivy can grow like a vine, pulling it out in one spot does not necessarily kill the plant.
Poison Ivy is also doing important work in the ecosystem. The network of vines and roots does an excellent job of preventing erosion, and the berries are an important food source for migratory birds in the fall.
And if you’re thinking about getting revenge on Poison Ivy and burning her, think again!
Urushiol volatilizes in smoke. That means you can inhale the poison and develop a rash in your lungs, which can be very dangerous and even fatal.
Where does poison ivy grow in Ontario?
Poison ivy is widespread in southern Ontario and grows as far north as Cochrane and Kenora.
It grows most abundantly south of Lake Huron and North Bay. Those are the most densely populated areas of the province, so for most Ontarians, there’s no way to escape!
Uh oh, I think I touched it… now what?
Be sure to wash any areas of your skin that may have come into contact with Poison Ivy with soap and cold water.
Remember: cold water is key! Using hot water to wash opens the pores, increasing the chances of absorbing urushiol.
While this may not prevent a reaction, it will probably prevent the spread of an infection. If a reaction develops, see your doctor for treatment.
Other facts impossible to skim
Some people confuse poison ivy and poison oak.
But poison oak is not found anywhere in Ontario.
Poison Oak and Poison Sumac are in the same genus as Poison Ivy. Sumac also grows in Ontario, of course, and contains the same harmful chemical: urushiol.
That means if you touch one and then the other, the effects can be aggravated.
Scientists estimate that 10 to 15 percent of us are immune to poison ivy.
But for the rest of us, our own immune system attacks our skin in the affected area.
For us unlucky ones, the more often we are exposed to the plant, the better our immune system will be at identifying the poison and the quicker it will respond, making the rash worse each time!
Humans (and possibly other primates) are the only animals known to develop a rash caused by poison ivy.
No other birds or mammals in Ontario have been found to react. But you still have to be careful: if your dog rubs against the plant, he could transfer it to you!