I'm often asked how I learn to identify wild plants. More specifically, How do I know that plant is edible? Disregarding the minor detail that the only person asking me this frequent question is myself, it's a good question. Here's a real-life narrative that answers that.
An unknown plant is growing in my yard. It's growing among the creeping Charlie ground ivy and henbit that I have already identified.
In this photo, the unknown plant is the larger one, in the upper, right-hand corner. A couple of henbits are standing tall, very close to the unknown. Creeping Charlie, a ground ivy, is covering the rest of the background, with some blades of grass in the lower, left-hand corner.
It looks tender and healthy. It reminds me of lettuce or plantain, but I just don't know what it is.
No doubt, there are many herbalists and wildcrafters who could tell me the name and characteristics of this plant. But for learning purposes, let's look at two principles involving safety and sureness, and then we'll start the process of identifying an unknown plant.
Principle #1: Safety
I will eat a plant only if I absolutely, with no doubt, know its identity. I suppose, in extreme circumstances, in danger of dying from hunger, I would cautiously nibble, and wait, and then eat a plant of which I am only somewhat sure of. But that is only when survival is at stake. Right now, I have no need to take chances.
Principle #2: Reference sources
Base your identification upon at least three trusted reference sources that agree. Be sure to compare the written descriptions with the actual plant. The most sure method of learning a plant's identity is with the guidance of another, more experienced guide who is absolutely confident and skilled in recognizing the plant.
Now, how shall I begin?
Step 1: Seasonal clues
This is a young plant. It's only been growing for perhaps the last month, and it's still very early in the year for plants. I do not feel confident that an attempt to identify this plant right now would be profitable. My knowledge of plant parts and plant identification is so basic, that I'm going to wait and watch.
It's early March right now. I'll keep an eye on this plant as it matures. Too many plants look too similar when they are young. When this plant begins to flower I should be able to find some obvious characteristics that will help me identify it.
In the meantime, I can browse for some pictures that might look similar to my unknown plant.
It might be a wild lettuce. The site doesn't give the scientific name, so that makes it harder to compare with with plants that share a common name, or when the same plant is known by different common names.
Here's a potential winner: Lactuca serriola.
This candidate actually seems the most likely: Sonchus oleraceus.
I think I'll have a much better idea in a month, so I'll withold judgement for right now, and I definitely will not nibble on it!