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Young Poison Ivy - Identification, Avoidance, Treatment

Birding / Hiking / Adventuring Roadtrip Info


Nov 2018
We are enthusiasts, not experts - read disclaimer.


  1. Intro - Why Young Plants Only
  2. Identification
  3. Urushiol - What Causes Injury
  4. Avoidance
  5. Treatment

1) Intro - Why Young Plants Only

This is about identifying YOUNG POISON IVY PLANTS. I wrote the entire thing before happening upon photos showing large ADULT poison ivy plants, saying "WTF! I've never seen that!" and deleting the article.

Then after doing a few trails I realized what I think is going on: People walk the most untended trails at least (I'd hope) once per year with an eye for clearing out the most obvious problems like huge poison ivy plants. What I always see are the young plants growing back in. Since that's mostly what we see and since it's at their height Cari gets the obvious contact (She reacts to it, I do not)  - I think maybe this is the important stuff to ID if you're on trails and not running through the woods off trail.

Also this is experience from Florida - things may get different further north.


2) Identification

First let me talk about what it's like to spot where it ought to be in the forest by zooming in with the camera. Afterwards I'll get into details of how to differentiate it from other plants that look pretty close.

Poison Ivy likes dark forests - not sunlight. If you're walking along a grass path it's pretty unlikely. It likes to be mixed in with 100 other small plants right there on the edge of the trail 0-10 inches off the ground under a shaded canopy of trees. It can be in small patches of sunlight inside forests however.

The following photo is a good example (Hillsborough River State Park).


That orange rectangle we will zoom into in the next photo.

But the point to get here is all that stuff that you'd think is grass were it your home is just many different species of plants. This is the kind of scene where you'd look for poison ivy.

Now to zoom in:


At this point you might be able to spot poison ivy - the leaves of 3... but several are in the shot. The next zoom is the orange rectangle again but I actually moved over it and used the flash:


I meant to photograph the two big sets of leaves but there's more poison ivy visible - one on the bottom right. Also I think the 2 little leaves in the top right of what's circled (the top leaf is bent under I think).

So that's an example of spotting it in real life. Now getting into how I learned to spot it quickly:

1) Shaded area as mentioned above.

2) The above photo you might notice it's hard to spot the stems. That's usually how they appear - as if they are leaf clusters hovering near the ground unconnected to a mother plant. As they get bigger they become more clearly part of a larger plant. Most looks like this on trails I've been on though.

3) More often than not the stems are sort of red near where the leaves are. That jumps out at me. But many do not have this - including this example above.

Here's an example from another trail. Not a great photo but you can see the stems are a little red.


4) It has clusters of "leaves of three' that are together a little bigger than the top of a cup of coffee. The photo up top had one with smaller leaves but generally they reach this size.

5) The clincher for poison ivy is it's symmetry. Look at this terrible thing I made in photoshop:


The three leaves are like a face and two hands. If you look at your face in the mirror you notice the left and right side are identical - unless you're injured. Hands however have a thumb on one side. Plus if you put one hand on the other so both are facing up you see they aren't identical (that's called chiarality). The center leaf in poison ivy is like a face - the left and right side of the leaf are the same. The outer two are not the same on each side of the leaf - it actually kind of looks like it has a thumb on the outside. That and those two side leaves are like hands in that they aren't identical but rather mirror images. Takes a lot of words to say that but once  you get out in the woods and start spotting it - it it's like riding a bike.

At first I noticed red stems on 3 leaved plants a certain size in shaded forests. Then I started cluing in more on the symmetry. Now when I see photos of adult plants it still seems clear - just the wrong sized plant.


 3) Urushiol - What Causes Injury


Nature is lazy - Urushiol is the same mix of oily compounds found in what you might call 3 classes of plants:
1) Mild: Mangos and cashews - very little urushil but enough that some people have allergic reactions. More on the skin and shell than the part eaten.
2) Medium: Poison Ivy, Poison Oak, Poison Sumac
3) Poisonwood  - It's a tree that literally weeps urushiol oil - it looks like paper after putting fried chicken on it. Much more of this stuff so do not get near it. It's only in south Florida though so not a big concern for most people.

I was under the impression that the deadly Manchineel tree - also only in south Florida - was an urushiol plant but turns out it works differently.

The three qualities of urushiol to be aware of

1) It is an oil so it will stick to your shoes, clothes, skin

2) It seeps into the skin (50% in 10 minutes) Also it can rub onto your skin later in the day when you take your shoes off etc.

3) People have an allergic reaction after it is under the skin - not from the top of the skin.

4) You can become more allergic at any time - especially after being exposed to a lot. I've never had a reaction even when rubbing it on my arm but if I was exposed to enough I could develop a terrible sensitivity.



4) Avoidance

It's an oil and to get it off you need soap (or alcohol - water won't do it alone). So avoid it best you can and wash it off. Also I'm no expert - this is just what I've picked up from reading about it and how Cari and I have dealt with it.:

1a) First thing to do is be aware if it is around or could be around. Most trails have little to none and I've never had a reaction even walking through tons of it so if there is a little around I don't think about it much. Cari on the other hand reacts badly - you can see where the one leaf brushed her skin in a line and she was miserable for several weeks from that. Below I'm assuming you are concerned about exposure on a given trip:

1b) Stay on trail. That solves most problems. A trail has to be quite under-used for poison ivy to grow ON the trail. It has to be thick with the stuff to brush against it from the sides usually. Get off trail and it can rub on your calves etc very easily.

2) Wear long pants or tall socks to keep it off your skin. But be very careful with cleanup...

3) Cleanup - You want to get the affected items off without getting it on your hands. So carry extra clothes and shoes. Put the dirty ones in a trash bag very carefully. Wear gloves while you do that or at least something like wetwipes or soap and water to make sure to get the oils off your hands. Be most careful with shoes.

4) At home - they sell professional products for this but I think all you really need to do is wash your stuff in hot soapy water - like most oils.


5) Treatment

By far the best treatment is avoidance. If you notice a reaction wash up everything ASAP because it does stick around. But after the reaction is triggered you really just have to live through it from what I understand. It's an immune response that's been triggered more than you having something on you after the initial exposure.

The only thing that worked for Cari other than just basic soothing creams etc is Apple Cider Vinegar - she said it worked VERY well. I'd love to hear the chemistry of that explained.

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