Plant Identification – How to be 100% positive about an ID

Almost every book, blog post, or article about foraging for wild edibles will contain a warning: Do not eat a plant unless you are 100% sure of its identity. The majority of plants are safe to eat, but there are some poisonous ones. And if consumed, some of those poisonous ones can have dire results, including death.

This warning has turned some people off from foraging, because they’re afraid of making a mistake. For beginners, a backyard may look like a sea of green, one type of plant indistinguishable from the next. How can you tell it all apart and know with 100% certainty which is edible?

There’s good news. Plant identification really isn’t difficult once you know some basics.

You can often identify a friend or family member with just a glance because you know their defining characteristics. Hair color and texture, skin color, height, weight, and the way they walk. Plants are the same. Spend some time observing them, noting the defining characteristics, and you’ll be able to pick out your favorites with a quick glance.

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Plant Identfication - How to be 100% positive about an ID

The best advice for learning to identify plants is to look, look, and look some more. Look at every part of the plant during different stages of its life cycle. Write down what you see and take a few clear photos. Make note of characteristics like the following:

  1. Stems and leaves are hairy or smooth (hairless)
  2. Stem shape – Cut a section of stem and look at the cut part. Is it round, square, or something else? Smooth or ridged? Solid or hollow?
  3. Clear or milky sap – Cut a green stem and look at what comes out
  4. Leaf shape
  5. Leaf margin (the edges of the leaves)   
  6. Simple or compound leaves 
  7. Alternate, opposite, or whorled leaves    
  8. Other leaf descriptions
  9. Color of flower and number of petals (Here’s a more in-depth look at flower terminology.)
  10. Color, size, and shape of nut/fruit (if any) 
  11. Bark pattern (when identifying trees)
  12. Time of year
  13. Environmental factors (dry, wet, hot, etc. which will effect size and speed of growth)

The list of characteristics could go on and on, including things like direction of leaf veins, color of leaf undersides, type of root system, and much more. If you find a plant that you want to identify, make note of every characteristic that you observe and take a few clear photos of different plant parts. Whether you go to an online source or ask someone local, the extra information will help.

Once you know something about parts of a plant, how do you find out if it’s edible or not? There is a treasure chest of resources, including books, bloggers, Facebook groups, and YouTube videos. If you find a local wild foods instructor, start there, since they’ll have info targeted to your area. A few of my favorite books are listed below, but look for a book that’s specific to your region.

Nature’s Garden: A Guide to Identifying, Harvesting, and Preparing Edible Wild Plants by Samuel Thayer
Edible Wild Plants: Wild Foods From Dirt To Plate by John Kallus
Wild Edibles: A Practical Guide to Foraging, with Easy Identification of 60 Edible Plants and 67 Recipes by Sergei Boutenko

Many foraging bloggers offer great descriptions for identifying plants, like Eat the Weeds, 3 Foragers, and The Foraged Foodie. I also have a Pinterest board: Wild Edibles – Identifying and Using Them. When you read something in a book or blog, compare it with others to make sure the info is accurate. Check multiple sources, since some writers will take from others when they don’t have personal experience.

Plant identification groups on Facebook are a big help when narrowing down plant ID. However, don’t blindly accept what you’re told. Double check the plant characteristics to see if the group has identified it correctly. Try the groups Edible Wild Plants, Plant Identification, Plant Identification and Discussion, and Plant Ident 101. There are also groups geared toward a specific country or region.

There are websites where you plug in the characteristics, and they name plants matching that description. These sites can provide a starting point, though I’ve rarely found them to be spot-on with an ID. Try What Tree is That? from the Arbor Day Foundation and  Weed ID from the University of Missouri. There are also numerous apps offering plant identification, though I’ve never tried them and the reviews are spotty.  Like the sites, they can provide a starting point but double check the responses. A site or app cannot compare to your own observations.

Wood Sorrel | The King's Table

Wood sorrel

All plants have defining characteristics, but they also have characteristics that vary by variety or species. Take wood sorrel for example (in the Oxalis family). One distinct characteristic is the heart-shaped leaves. No matter the variety, the leaves will always be the same shape. But depending on variety, the flowers can be white, yellow, pink, or violet. Bloggers and other writers will write about the type common in their areas. You could be told to look for pink flowers when the yellow flowered variety grows in your backyard. This is why it’s important to find a local wild edibles instructor and to obtain a descriptive book of your area’s plants. Online writers are a good place to start, but local resources can tell you which variety to look for.

Learn about toxic look-alikes. Some poisonous plants look a little similar to wild edibles, so it’s important to know what to look for. You don’t want to assume it’s a different variety of a wild edible when it’s actually a completely different plant. For example, poisonous spurge is occasionally mistaken for the edible purslane. But once you know what to look for, it’s easy to tell the difference.   

Before consuming a plant, it’s important to know which parts are edible, if any special preparation is necessary, the best time to harvest during the plant’s life cycle, and if it’s edible in large amounts or only smaller doses. Just because someone says “acorns are edible” doesn’t mean you should crack fresh acorns and eat them by the handful. Know the details. Yes, acorns are edible, but they need to be soaked (i.e. properly prepared) to remove the bitter tannins.

So, how can you identify an edible plant with 100% certainty? Observe and read. Look closely at the plants, and read what other foragers have to say. NEVER force a plant to fit a description by thinking  “Well, it meets 2 out of 3 characteristics.” Lastly, try a small bite after you’ve positively identified the plant. People can react to anything, so see how your body responds before you eat a full meal of it.

What are your favorite foraging or plant identification resources?

Related Posts:
Identifying Sheep Sorrel
Identifying Henbit


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