The first non-edible plant

In the car Sparkle started asking me about edible plants. Edible plants are Wander's realm, but he wasn't available. She wanted to know how Wander knew which plants are edible and which aren't. I explained how he didn't personally test each plant, but rather read books and talked with other people. Those other people learned which plants are edible from other people, on back in time. Before books, people learned via word of mouth. Of course, if you go back far enough in time, people had to learn by eating the plants and seeing what happened. Perhaps someone plucked a berry and ate it, and then got sick. Other people would then know that those berries are poisonous and not eat them.

A lightbulb went on in Sparkle's mind. We had been talking about to Adam and Eve earlier this week. She reasoned that they were the first to discover that some plants are edible and others are not, and ever since their time, people have known not to eat certain plants.