Home farming How to Identify Wild Poisonous Plants – The Essential Guide

How to Identify Wild Poisonous Plants – The Essential Guide



1. Knowing a few additional tips can help you identify at least some of the most common poisonous plants—poison ivy and poison oak—which are prevalent in most areas of the country.

Threeinone isn’t fun. The rule “leaves in three, let it be!” really means this: no leaf on a poison ivy or poison oak plant is an individual. Every leaf has three leaflets, which grows off a common stem, which grows off a branch. So if you see three leaves at the end of a branch, continue inspecting the branch toward the body of the plant. Is every single leaf actually three leaflets (each with their own short stems), growing off a main leaf stem, growing off a branch?  Then yes!  It’s poisonous! If no, it’s not poison ivy or poison oak, thank goodness.

How to Identify Poisonous Plants


poison oak leafAlternate isn’t great. (Okay, it’s an awkward phrase, but it’s true.) Poison ivy and poison oak have features that alternate. The leaf stems alternate on the branch—they are never directly opposite each other. The veins on the leaflets (each poison ivy and poison oak leaf is made up of three leaflets; this is what is meant by “leaves in three, let it be!”) alternate and are never directly opposite each other. Any flowers growing on the plants alternate on the flower branches; they are never directly opposite each other. Handy, right?How to Identify Poisonous Plants


For more tips like this and a handy printable guide (so you can include it in your wilderness pack), “The Sure-Fire Poison Oak and Poison Ivy Identification System.”

2. Fortunately, the world abounds with resources designed to familiarize you with the specifics of poisonous plants that might be indigenous to the wild areas of your region (see resources at the end of this article).


It’s important to note that some common decorative plants can be toxic to the touch. While they’re unlikely to kill you unless you ingest them—DON’T INGEST THEM!—it might be best to steer clear of them entirely. Two are particularly common, beautiful, and irritating.

OleanderHow to Identify Poisonous PlantsThe beautiful flower of this evergreen shrub is drought tolerant and repellant to deer (who wisely won’t eat this toxic plant). But it’s deadly to ingest (I’ll SAY IT AGAIN—DON’T INGEST IT!), and its sap can be poisonous to touch. Be sure to use gloves when handling it, don’t touch your eyes or mouth, and/or just get rid of the darned pretty things. Who needs the risk?


How to Identify Poisonous Plants

Lovely stalks with purply-blue, wing-like flowers, monkshood is a likely garden choice, except for its highly toxic nature. Even touching the plant can allow the toxin in through your skin, which can cause tingling, numbness, and/or damage to your heart.


If, after exposure to vegetation, you feel tingling, see a rash, or otherwise experience some kind of physical reaction, your best responses are these:

  1. Try to determine what plant might have caused a physical reaction; follow any plant-specific care directions you may find in the above plant guides or in other resources, such as A Comprehensive Guide to Wilderness and Travel Medicine Book.
  2. If you don’t have a guide or specific directions for treatment, rinse the location with water and disinfectant, being careful not to transfer the irritant to another part of your body or to your clothing (if that’s possible). Have a kit on hand like the Professional Outdoor Skin Protection Kit with Soft Case to help you rinse and soothe the affected area.
  3. If your response persists despite treatment, affects your breathing or heart rate, or causes more than just a mild reaction on your skin, call your healthcare provider or poison control.


Remember: When in doubt, do not touch!  A poisonous plant puts the “ouch” in touch. My brothers can attest to that.

What lessons have you learned from your experiences with sneaky (aka poisonous) plants?

Originally Published in Be Perpared