There’s probably nothing worse than eating something that either makes you sick as a dog or possibly killing you.  When it comes to foraging for food, this is a possibility unless you can positively identify what you’re about to eat.  In a survival situation, you may not have that luxury.  That being said, there are steps you can take to protect yourself (and your stomach) under such circumstances.  It’s called the universal edibility test (UET).  Even with something you’ve positively identified, it’s not a bad idea to do this test, just in case you are allergic to whatever it is you’re testing.  What follows (or at least a version) comes out of just about any book on survivalism and/or field guide for edible wild plants.

  Another thing to keep in mind is, is it worth it to test a plant if there’s not enough in the area to make the test worth it?  Basically, do you want to test a strange plant and risk getting sick if it’s the only plant of it’s type that you see?  Only you can make that call, but keep in mind that if you get sick in a survival situation, you could be out of action for hours or days, time which could mean the difference between life and death if you have to forage for food/fuel/fluids/etc.

  First and foremost, generally speaking, you want to avoid the following unless otherwise noted for the plant you’re foraging for:

• If it has a milky or odd colored sap
• Beans, bulbs, or seeds inside pods
• Bitter or soapy tasting
• Spines, fine hairs, or thorns
• Dill, carrot, parsnip, or parsley-like foliage
• “Almond” scent in woody parts and leaves
• Grain heads with pink, purplish, or black spurs
• Three-leaved growth patterns ( leading to the saying “Leaves of 3, leave it be”)

  Just following this list will help you avoid a lot of trouble and discomfort by avoiding plants that can cause distress by just touching or eating.  As a side note, try to make sure you wash your hands before and after handling/testing strange plants.  One, it will help determine, in the unfortunate case of getting sick, that it was indeed the plant you sampled instead of something you got on your hands before the test, and to make sure that if it was an irritant/poisonous, it hopefully won’t spread too far on your body.

  Once you’ve gotten through all that, now we get into the heart of the test:

1. Test only one part of the plant in question at a time.  For example, if you’re going to test the leaves for edibility, don’t also try the roots.  Some plants have poisons in one part of the plant but not other parts.
2. With this in mind, separate the plant into it’s component parts. I.E. stems, leaves, flowers, roots, etc.  Smell, taste, or texture doesn’t alone indicate whether it’s something that’s good or bad to eat.  If that were the case, nobody would eat limburger cheese....
3. Smell the plant part for strong odors, especially anything that smells acidic.
4. Fast for at least 8 hours before testing the plant part.  That way, again, you know if any issue is directly caused by the plant part and not something you ate previously.
5. While you’re waiting, test the plant part for any type of contact poisons.  Best places (unfortunately) for testing this stuff is on tender skin areas, like the inside of the wrist or possibly the inside of your elbow.  If it’s bad for you, it’s probably going to cause a reaction in 30 min or less.  There are possible exceptions to this, but again, these are general rules.
6. Also during the wait, the only thing you should put in your mouth/body is purified water.
7. After 8 hours, now we get into the good stuff.  Assuming you didn’t have a reaction in the previous steps, the next thing you do is to take said plant part (small portion, i.e. a leaf or two at most, one or two berries, etc.) and fix it like you plan to eat it.  Are you going to boil it?  Some poisons are removed/neutralized by boiling, most aren’t.
8. Next, before you put it in your mouth after preparing, touch a small portion on the outer portion of your lip.  What you’re checking for is any sensation of burning or itching.  If nothing within 3-5 minutes, Next, rub a small portion on same area, checking for the same reaction and for the same amount of time.
9. If after these two tests with no reaction, place said portion on your tongue, not chewing it or doing anything except letting it sit on your tongue for 15 minutes, again checking for any type of bad sensation or burning/itching/swelling.
10. Next step, assuming nothing has happened at this point, is to chew said section completely, but don’t swallow it, and again wait 15 minutes to allow time for the item to cause a sensation/reaction.
11. Assuming you haven’t died, (or had anything like a numbing sensation, burning, itching, swelling, or any other adverse reaction), swallow the sample.
12. Now you get to wait for another 8 hours to see if you have any adverse reaction.  On an empty stomach, it should be able to get through most, if not all, of your digestive track.  If you start to feel sick, try to induce vomiting (ipecac would be a handy substance here if you have room in your kit) and/or drink plenty of water, the more the better.
13. If you don’t have anything bad happen or getting sick, the next step is to prepare the same way a 1/4 cup worth of the same plant part and and eat it.  Wait another 8 hours.  If nothing bad happens, the plant part, as prepared, is safe for eating.  I would recommend if possible slowly scaling up the quantity of the material you’re eating for the possibility that what you’re eating may be harmful to you in large quantities.  Better to be safe than sorry.
14. Repeat process for the next part of the plant you want to test.

  Yes, it’s a big headache to do and you’re going to be going hungry for a long time at a shot, but something to keep in mind.  You don’t have to do ALL the steps at once.  You can do the small sample test, then if good, eat what you’ve been eating normally, then start the test again the next day after waiting for your 8 hours before trying the 1/4 cup of the plant.  That way, you’re less likely to rush the test in the name of being hungry.  Another thing to keep in mind, as mentioned previously, is don’t assume that something that was cooked is also safe raw.  You have to test each part separately as you would prepare it to eat it.  Don’t risk your life on it.