Beginning foragers are often stymied by the overwhelming sea of green plants that surround us in any wild area. People often lament to me that they can’t tell a “pine from an oak” and that “it all looks the same – green!” Well, here’s where I hand you the keys to the kingdom (the plant kingdom, anyway). The differences aren’t about colors or size, the key is in the shapes and forms. By understanding the different parts of a plant and the role that anatomy plays in identification, you’ll have the tools to identify any plant like a pro.
Woody or Fleshy?
You can start your identification here or wrap it up with this aspect, but it sure is easier to know which book to use (the tree and shrub guide – or the wildflower book).
Is It Herbaceous? The herbaceous group of plants is a softer, fleshier category of plants. Many of these are considered annual plants (living only one year before going to seed and dying), though some can live for two or more years. In the case of the latter, a plant may have a root that stays alive for a few years, but all of the “above ground” parts die back completely each winter. There are no persistent, woody stems above ground that stay alive from year to year (the way shrubs, vines, and trees do).
Is It Woody? These plants are exactly what they sound like. They are plants that have woody stems, branches, or trunks, and the group includes trees, shrubs, and most vines. This group produces woody tissues from primary and secondary xylem, which are typically sheathed with cork-like material that we know as bark.
This outer secondary xylem (the sapwood) moves water through the woody plant, while the inner part (the heartwood) is formed from dead (but still strong) primary xylem. In colder climates, we can tell the age of a tree by counting the number of annual xylem rings. Since this woody growth stays alive and keeps growing, year after year, the woody plant group contains our largest terrestrial plants.
If you’re looking for a “cheat sheet” to get you started, plant flowers can often give you a great way to differentiate one species from another – in a hurry. The first half of Peterson’s field guide to Edible Wild Plants is divided by flower color, then petal number, then some finer details. This kind of key system can easily fail us since plants aren’t “in flower” from the second they sprout until the time they are dying back, but if you’re lucky enough to stumble across a mystery plant while it is in flower, pay close attention to the flower’s structure. This can tell you exactly which species you are seeing. Look at flower color, petal number, stamen number, stamen color, the pistils, hairs, spots, and any other parts or features you can see. Break out your magnifying glass or use your phone camera on “zoom” for a closer look.
When I show one of my foraging classes a new fruit or berry, we key in first on the skin color and any noticeable external features. A few foraging books do divide the plants by fruit or berry color, and this is a vital part of your identification – but it’s just the start. Here’s what you need to look at when studying fruit.
- Fruit color – obvious, but important
- External features – Is it freckled? Is there a dimple on the end? Shape?
- Pulp color – Does it match the skin, or is it a different color?
- Pulp texture – Is the pulp watery, pasty, mealy, dry, fleshy, slimy?
- Seed number – This can be a deal-breaker! Count the number of seeds from multiple fruits and find the average.
- Seed color – This is another major player. How would you describe the color?
- Seed size – Is it tiny, medium, huge?
- Seed shape – There’s a surprising variety of seed shapes, and the seeds in your fruit should match the book’s description perfectly.
The first half of Peterson’s edibles is based on flowers and is filled mostly with herbaceous plants, but the second half of the book gets really interesting. It’s based on the way that plants branch out, and mainly deals with woody plants. When looking at the branch pattern and leaf structure, we get four common groups of plants. These are alternate simple, alternate compound, opposite simple and opposite compound. This provides any forager with a fast framework to divide plants into smaller groups and rule out most of the wrong plants with just a quick look at the leaves and branches. No flowers are required. Here’s what all that alternate/opposite stuff really means.
Alternate Branching Most of the plants on earth share this common pattern, which is an alternating (zig-zag pattern) on the leaves, twigs, and branches. Pine trees, greenbrier vines, and most plants grow in this “right, left, right, left” pattern.
Opposite Branching This pattern has leaves, twigs, and branches that grow opposite of each other (like arms on a body). There is symmetry here unless the odd leaf, twig, or branch died or never grew. Opposite branching is seen in maple, ash, dogwood, buckeye and horse chestnut trees. Plenty of herbaceous plants have this pattern, too, like mint and chickweed.
Simple Leaves Most of the plants we see will grow simple leaves. And despite individual leaf complexity (like lobes and teeth), simple leaves have just one body and one leaf stem.
Compound Leaves The compound leaf grows multiple leaflets along a fleshy leaf stalk, and even though there are many separate pieces – it still only counts as a single leaf. These are easiest to discern in autumn as the leaflets begin to drop, and eventually, even the leaf stalk drops off the twig. One other feature is that compound leaves generally create a large “leaf scar” when they drop off a twig (since the compound leaf stalks are typically thicker than simple leaf stems).
Get to know these four groups:
- Alternate simple – the most common pattern for plant growth (oak is one)
- Alternate compound – less common, but plentiful (walnut is an example)
- Opposite simple – less common (maple is an example)
- Opposite compound – the least common (ash trees are an example)
Learn The Scientific Name
So many of the plants that we would commonly forage have multiple names. They might be called one name in a certain region, something else in a different area (even though we’re talking about the same plant). Worse still, two foragers might have a common name that sounds the same, but they’re actually thinking of two completely different plants. Scientists came up with a solution to this problem centuries ago, and today we call it the scientific name. Even though these still change from time to time (as people learn more about plant relationships and plant genetics), these nerdy names are the way to go!
Each known species has a two-part scientific name (called “binomial nomenclature”). There will be a lot of Latin and Greek involved, and sometimes the names of botanists. The names we need to concern ourselves with as foragers are the family, genus, and species. The family name is a large group, which share some basic features. Then comes the genus. This literally means “generic,” and it’s a smaller group within the family. Finally, we come down to species. This is the “specific” name of a unique organism. This is what really matters, as one species may be good food while another is not edible – even if they share the same genus and family. At the end of the day, the scientific names are hard to spell, even harder to pronounce and worth all the trouble. They allow us to research plant details without fear of reading about the wrong plant, and they let us converse without so much confusion. Take the time to learn them.