Photo by Melody

Article: Poison Ivy: Identification, Treatment, and Removal: urushiol - a plant defense?

Communities > Forums > Article: Poison Ivy: Identification, Treatment, and Removal
Forum: Article: Poison Ivy: Identification, Treatment, and RemovalReplies: 3, Views: 17
Add to Bookmarks
Orlando, FL

October 1, 2012
7:47 AM

Post #9291995

The pain from a nettle or thorn is immediate, you see the plant and learn to avoid it even if you have the brains of a cow :) The reaction to urushiol occurs hours or days later, tough to draw a connection unless you have some cultural information to rely on. Also, it seems that humans are the only ones who have an allergic reaction, and we are not predators of the plant. I tried to find info on what plants use urushiol compounds for to no avail. My guess would be our allergic reaction is an unfortunate coincidence to a compound the plant is using for a purpose that has nothing to do with us. Anthropocentrism strikes again!


Mackinaw, IL
(Zone 5a)

October 1, 2012
6:53 PM

Post #9292971

Many of the plants that cause severe contact dermatitis produce urushiol. I am also working on articles on two others, poison oak and poison sumac. Someone asked me if you could tell which plant had caused the rash, based on the reaction, which is what got me looking into this topic in the first place. The answer is that they all three produce urushiol, which is what causes the reaction, so the rashes are indistinguishable from each other.

Many sources I read in researching this article referred to the production of urushiol as a defense mechanism. I wonder if the urushiol has an unpleasant flavor, preventing grazing animals from eating it, and our allergic reaction is a secondary effect. I certainly haven't ever seen any animals eating it, or even many signs of insect damage on the leaves.

Stanchfield, MN

October 1, 2012
8:50 PM

Post #9293124

Booker, I have seen definite evidence of deer, and possibly rabbits, browsing on Poison Ivy, and there are at least two insects that eat the leaves (although I don't recall right now which ones they are). And birds definitely do eat the berries.
Dover, PA

October 10, 2014
9:53 AM

Post #9956340

Excellent article (for the most part)! I was advised by many people that I "need to get a goat" when I mentioned the poison ivy infested pasture on the derelict property I purchased. They are supposed to LOVE the stuff. Urushiol may serve some evolutionary purpose, but predatory deterrence does not seem to be the answer.

You cannot post until you register and login.

Other Article: Poison Ivy: Identification, Treatment, and Removal Threads you might be interested in:

SubjectThread StarterRepliesLast Post
My Horrible Posion Ivy Experience KittyWittyKat 5 Oct 1, 2012 8:39 PM
Avocado amygirl 1 Oct 1, 2012 6:46 PM
Very Interesting Article gardengirl86 4 Oct 4, 2012 1:58 PM
Poison ivy violetdundas 3 Oct 11, 2014 1:56 PM
Poison Oak the_naturalist 1 Oct 1, 2012 7:10 PM

Overwhelmed? There's a lot to see here. Try starting at our homepage.

[ Home | About | Advertise | Media Kit | Mission | Featured Companies | Terms of Use | Tour | Rules | Privacy Policy | Cookie Policy | Contact Us ]

Back to the top

Copyright © 2000-2015 Dave's Garden, an Internet Brands company. All Rights Reserved.

Hope for America