Comparing Edible and Inedible Plants

Some plants, such as herbaceous plants (peonies) and crab apple (Malus floribunda) trees, are things that humans can eat. Other plants like wild cherry trees (Prunus avium) are plants humans can not eat. This phenomenon will lead students to a deeper understanding of which plants are safe to eat and which ones are not so that they can protect themselves while exploring in the wild. This is a crabapple (Malus floribunda) tree, which is an edible plant in Iowa.

Driving Question

How do we identify which plants we can and cannot eat based on personal investigations in Iowa? 

Probing Questions

• What properties have you noticed about edible plants in the environment or area where you live? Inedible plants? Think about fruits and vegetables that you eat and see during everyday life and plants that you see while playing outside.
• Where have you seen edible plants around home (in Iowa)? Go on an adventure to find edible and inedible plants.
• What environments can we find plants that are edible in? Inedible? Where are those environments found near your house/school?

Classroom Suggestions

Students could:

• Picture Analysis: Compare and contrast pictures of multiple edible plants. Then, compare and contrast pictures of inedible plants. Lastly, compare and contrast pictures of both edible and inedible plants. Identify characteristics of both and discuss.
• Plant Dissection Lab: First, break open the stem of a plant. If the stem has a milky liquid inside, it is poisonous to eat. If the inside of the stem is not milky, it is safe to eat. Next, smell the plant. Almond (unless it is an almond) or chemical smells are often poisonous. If plants look like a plant that you know is safe to eat, but it does not smell like that plant, it is poisonous. For example, if you think you are holding an onion, but it does not smell like an onion, it is not safe to eat.
• Make Your Own Rule Activity: A typical rule to avoid poison ivy is “Leaves of three, let it be.” Have students look at a variety of Inedible plants (pictures or real) and have them create their own rules to determine if it is a safe plant.
• Edible Plant Scavenger Hunt: Go to a state park or nature preserve such as Backbone State Park or Hartman Reserve and look for plants that are edible. You can also take pictures of edible and inedible plants that you find and sort them after your scavenger hunt.

Resources

• OSMETv | How to Test if a Plant is Poisonous: Testing Poisonous Plants: This is a video about testing plants in the wilderness that may be helpful for the experiment in the classroom.
• Gregory the Terrible Eater book by Mitchell Sharmat and illustrated by Jose Aruego and Ariane Dewey: This book is about a goat who eats inedible things such as tires and violins rather than the fruits, vegetables, and other foods that goats should eat. Because of this, his parents take him to the doctor to see if he is healthy.